draft-ietf-nntpext-base-05.txt   draft-ietf-nntpext-base-06.txt 
INTERNET DRAFT S. Barber INTERNET DRAFT S. Barber
Expires: September 30, 1998 Academ Consulting Services Expires: January 7, 1999 Academ Consulting Services
March 1998 August 1998
Network News Transport Protocol Network News Transport Protocol
draft-ietf-nntpext-base-04.txt draft-ietf-nntpext-base-06.txt
1. Status of this Document 1. Status of this Document
This document is an Internet-Draft. Internet-Drafts are This document is an Internet-Draft. Internet-Drafts are
working documents of the Internet Engineering Task Force working documents of the Internet Engineering Task Force
(IETF), its areas, and its working groups. Note that other (IETF), its areas, and its working groups. Note that other
groups may also distribute working documents as Internet- groups may also distribute working documents as Internet-
Drafts. Drafts.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or made obsolete by other months and may be updated, replaced, or made obsolete by other
documents at any time. It is inappropriate to use Internet- documents at any time. It is inappropriate to use Internet-
Drafts as reference material or to cite them other than as Drafts as reference material or to cite them other than as
"work in progress." "work in progress."
To learn the current status of any Internet-Draft, please To learn the current status of any Internet-Draft, please
check the "1id-abstracts.txt" listing contained in the check the "1id-abstracts.txt" listing contained in the
Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), Internet-Drafts Shadow Directories on ftp.is.co.za (Africa),
nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim),
ds.internic.net (US East Coast), or ftp.isi.edu (US West ftp.ietf.org (US East Coast), or ftp.isi.edu (US West
Coast). Coast).
This document is a product of the NNTP Working Group, chaired This document is a product of the NNTP Working Group, chaired
by Ned Freed and Stan Barber. by Ned Freed and Stan Barber.
2. Abstract 2. Abstract
The Network News Transport Protocol has been in use in the The Network News Transport Protocol has been in use in the
Internet for a decade and remains one of the most popular Internet for a decade and remains one of the most popular
protocols (by volume) in use today. This document is a protocols (by volume) in use today. This document is a
replacement for RFC 977 and officially updates the protocol replacement for RFC 977 and officially updates the protocol
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net news articles over a reliable full duplex communication net news articles over a reliable full duplex communication
method. method.
Every attempt is made to insure that the protocol Every attempt is made to insure that the protocol
specification in this document is compatible with the version specification in this document is compatible with the version
specified in RFC 977[1]. However, this version does not specified in RFC 977[1]. However, this version does not
support the ill-defined SLAVE command and permits four digit support the ill-defined SLAVE command and permits four digit
years to be specified in the NEWNEWS and NEWGROUPS commands. years to be specified in the NEWNEWS and NEWGROUPS commands.
It changes the default character set to UTF-8[2] instead of It changes the default character set to UTF-8[2] instead of
US-ASCII[3]. It also makes extends the newsgroup name matching US-ASCII[3]. It also extends the newsgroup name matching
capabilities already documented in RFC 977. capabilities already documented in RFC 977.
Generally, new functionality is available using new keywords. Generally, new functionality is available using new keywords.
Part of that new functionality involves a mechanism to Part of that new functionality involves a mechanism to
discover what new functionality is available to clients from a discover what new functionality is available to clients from a
server. server.
This mechanism can also be used to add more functionality as This mechanism can also be used to add more functionality as
needs merit such additions. needs merit such additions.
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CONNECTION CONNECTION
GREETING GREETING
DISCONNECTION DISCONNECTION
Other steps may occur between the GREETING and DISCONNECTION Other steps may occur between the GREETING and DISCONNECTION
step. They are: step. They are:
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CAPABILITIES DISCOVERY CAPABILITIES DISCOVERY
AUTHENTICATION
NEWS EXCHANGE NEWS EXCHANGE
CONCLUSION CONCLUSION
NNTP operates over any reliable data stream 8-bit-wide NNTP operates over any reliable data stream 8-bit-wide
channel. When running over TCP/IP, the official port for the channel. When running over TCP/IP, the official port for the
NNTP service is 119. Initially, the server host starts the NNTP service is 119. Initially, the server host starts the
NNTP service by listening on a TCP port. When a client host NNTP service by listening on a TCP port. When a client host
wishes to make use of the service, it MUST establish a TCP wishes to make use of the service, it MUST establish a TCP
connection with the server host by connecting to that host on connection with the server host by connecting to that host on
the same port on which the server is listening. This is the the same port on which the server is listening. This is the
CONNECTION step. When the connection is established, the NNTP CONNECTION step. When the connection is established, the NNTP
server host MUST send a greeting. This is the GREETING step. server host MUST send a greeting. This is the GREETING step.
The client host and server host then SHOULD then exchange The client host and server host SHOULD then exchange commands
commands and responses (respectively) until the connection is and responses (respectively) until the connection is closed or
closed or aborted. This final step is called the DISCONNECTION aborted. This final step is called the DISCONNECTION step.
step.
If there is a CONCLUSION step, it MUST immediately precede the If there is a CONCLUSION step, it MUST immediately precede the
DISCONNECTION step. There MUST be only one CONNECTION, DISCONNECTION step. There MUST be only one CONNECTION,
CONCLUSION and DISCONNECTION step for each NNTP session. All CONCLUSION and DISCONNECTION step for each NNTP session. All
other steps MAY be repeated as needed. other steps MAY be repeated as needed.
The character set for all NNTP commands is UTF-8. Commands in The character set for all NNTP commands is UTF-8. Commands in
the NNTP MUST consist of an US-ASCII case-insensitive keyword, the NNTP MUST consist of an US-ASCII case-insensitive keyword,
which MAY be followed by one or more arguments. An US-ASCII which MAY be followed by one or more arguments. An US-ASCII
CRLF pair MUST terminate all commands. Multiple commands MUST CRLF pair MUST terminate all commands. Multiple commands MUST
NOT be permitted on the same line. Keywords MUST consist of NOT be permitted on the same line. Keywords MUST consist of
printable US-ASCII characters. Unless otherwise noted printable US-ASCII characters. Unless otherwise noted
elsewhere in this document, Arguments SHOULD consist of elsewhere in this document, Arguments SHOULD consist of
printable US-ASCII characters. Keywords and arguments MUST be printable US-ASCII characters. Keywords and arguments MUST be
each separated by one or more US-ASCII SPACE or US-ASCII TAB each separated by one or more US-ASCII SPACE or US-ASCII TAB
characters. Keywords MUST be at least three US-ASCII characters. Keywords MUST be at least three US-ASCII
characters and MUST NOT exceed 12 US-ASCII characters. characters and MUST NOT exceed 12 US-ASCII characters.
Command lines MUST NOT exceed 512 octets, which includes the Command lines MUST NOT exceed 512 octets, which includes the
terminating US-ASCII CRLF pair. terminating US-ASCII CRLF pair. Arguments must not exceed 497
octets.
Each response MUST start with a three-digit status indicator Each response MUST start with a three-digit status indicator
that is sufficient to distinguish all responses. Responses to that is sufficient to distinguish all responses. Responses to
certain commands MAY be multi-line. In these cases, which are certain commands MAY be multi-line. In these cases, which are
clearly indicated below, after sending the first line of the clearly indicated below, after sending the first line of the
response and an US-ASCII CRLF, any additional lines are sent, response and an US-ASCII CRLF, any additional lines are sent,
each terminated by an US-ASCII CRLF pair. When all lines of each terminated by an US-ASCII CRLF pair. When all lines of
the response have been sent, a final line MUST be sent, the response have been sent, a final line MUST be sent,
consisting of a termination octet (US-ASCII decimal code 046, consisting of a termination octet (US-ASCII decimal code 046,
".") and an US-ASCII CRLF pair. If any line of the multi-line ".") and an US-ASCII CRLF pair. If any line of the multi-line
response begins with the termination octet, the line MUST be response begins with the termination octet, the line MUST be
"byte-stuffed" by pre-pending the termination octet to that "byte-stuffed" by pre-pending the termination octet to that
line of the response. Hence, a multi-line response is line of the response. Hence, a multi-line response is
terminated with the five octets "CRLF.CRLF" (in US-ASCII). terminated with the five octets "CRLF.CRLF" (in US-ASCII).
When examining a multi-line response, the client MUST check to When examining a multi-line response, the client MUST check to
see if the line begins with the termination octet. If so and see if the line begins with the termination octet. If so and
if octets other than US-ASCII CRLF follow, the first octet of if octets other than US-ASCII CRLF follow, the first octet of
the line (the termination octet) MUST be stripped away. If so
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the line (the termination octet) MUST be stripped away. If so
and if US-ASCII CRLF immediately follows the termination and if US-ASCII CRLF immediately follows the termination
character, then the response from the NNTP server is ended and character, then the response from the NNTP server is ended and
the line containing ".CRLF" (in US-ASCII) MUST NOT considered the line containing ".CRLF" (in US-ASCII) MUST NOT considered
part of the multi-line response. part of the multi-line response.
A NNTP server MAY have an inactivity autologout timer. Such a A NNTP server MAY have an inactivity autologout timer. Such a
timer MUST be of at least three minutes duration. The receipt timer MUST be of at least three minutes duration. The receipt
of any command from the client during that interval should of any command from the client during that interval should
suffice to reset the autologout timer. When the timer suffice to reset the autologout timer. When the timer
expires, the server should close the TCP connection without expires, the server should close the TCP connection without
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5xx - Command unimplemented, or incorrect, or a serious 5xx - Command unimplemented, or incorrect, or a serious
program error occurred. program error occurred.
The next digit in the code indicates the function response The next digit in the code indicates the function response
category. category.
x0x - Connection, setup, and miscellaneous messages x0x - Connection, setup, and miscellaneous messages
x1x - Newsgroup selection x1x - Newsgroup selection
x2x - Article selection x2x - Article selection
x3x - Distribution functions x3x - Distribution functions
x4x - Posting x4x - Posting
x5x - Authentication and Authorization
x8x - Nonstandard (private implementation) extensions x8x - Nonstandard (private implementation) extensions
x9x - Debugging output x9x - Debugging output
The exact response codes that MUST be expected from each The exact response codes that MUST be expected from each
command are detailed in the description of the keyword that is command are detailed in the description of the keyword that is
the first part of the command. In addition, below is listed a the first part of the command. In addition, below is listed a
general set of response codes that MAY be received at any general set of response codes that MAY be received at any
time. time.
Certain status responses contain parameters such as numbers Certain status responses contain parameters such as numbers
and names. In those cases, the number and type of such and names. In those cases, the number and type of such
parameters MUST be fixed for each response code to simplify parameters MUST be fixed for each response code to simplify
interpretation of the response. In all other cases, the client interpretation of the response. In all other cases, the client
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MUST only use the response code itself to determine the nature MUST only use the response code itself to determine the nature
of the response. of the response.
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Parameters MUST be separated from the numeric response code Parameters MUST be separated from the numeric response code
and from each other by a single US-ASCII space. All numeric and from each other by a single US-ASCII space. All numeric
parameters MUST be in base 10 (decimal) format, and may have parameters MUST be in base 10 (decimal) format, and may have
leading zeros. All string parameters MUST begin after the leading zeros. All string parameters MUST begin after the
separating space, and MUST end before the following separating separating space, and MUST end before the following separating
space or the US-ASCII CRLF pair at the end of the line. space or the US-ASCII CRLF pair at the end of the line.
(Therefore, string parameters MUST NOT contain US-ASCII (Therefore, string parameters MUST NOT contain US-ASCII
spaces.) All text, if any, in the response which is not a spaces.) All text, if any, in the response which is not a
parameter of the response must follow and be separated from parameter of the response must follow and be separated from
the last parameter by an US-ASCII space. Also, note that the the last parameter by an US-ASCII space. Also, note that the
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either the 4XX or 5XX group as appropriate. either the 4XX or 5XX group as appropriate.
5. The WILDMAT format 5. The WILDMAT format
The WILDMAT format[5] was first developed by Rich Salz based The WILDMAT format[5] was first developed by Rich Salz based
on the format used in the UNIX "find" command to articulate on the format used in the UNIX "find" command to articulate
file names. It was developed to provide a uniform mechanism file names. It was developed to provide a uniform mechanism
for matching patterns in the same manner that the UNIX shell for matching patterns in the same manner that the UNIX shell
matches filenames. Patterns are implicitly anchored at the matches filenames. Patterns are implicitly anchored at the
beginning and end of each string when testing for a match. beginning and end of each string when testing for a match.
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There are five pattern-matching operations other than a strict There are five pattern-matching operations other than a strict
one-to-one match between the pattern and the source to be one-to-one match between the pattern and the source to be
checked for a match. The first is an asterisk (*) to match any checked for a match. The first is an asterisk (*) to match any
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sequence of zero or more UTF-8 characters. The second is a sequence of zero or more UTF-8 characters. The second is a
question mark (?) to match any single UTF-8 character. The question mark (?) to match any single UTF-8 character. The
third specifies a specific set of characters. The set is third specifies a specific set of characters. The set is
specified as a list of characters, or as a range of characters specified as a list of characters, or as a range of characters
where the beginning and end of the range are separated by a where the beginning and end of the range are separated by a
minus (or dash) character, or as any combination of lists and minus (or dash) character, or as any combination of lists and
ranges. The dash can also be included in the set as a ranges. The dash can also be included in the set as a
character it if is the beginning or end of the set. This set character it if is the beginning or end of the set. This set
is enclosed in square brackets. The close square bracket (]) is enclosed in square brackets. The close square bracket (])
may be used in a set if it is the first character in the set. may be used in a set if it is the first character in the set.
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6. Format for Keyword Descriptions 6. Format for Keyword Descriptions
On the following pages are descriptions of each keyword On the following pages are descriptions of each keyword
recognized by the NNTP server and the responses that will be recognized by the NNTP server and the responses that will be
returned by those commands. These keywords are grouped by the returned by those commands. These keywords are grouped by the
functional step in which they are used. functional step in which they are used.
Each keyword is shown in upper case for clarity, although the Each keyword is shown in upper case for clarity, although the
NNTP server ignores case in the interpretation of commands. NNTP server ignores case in the interpretation of commands.
Any parameters are shown in lower case. A parameter shown in Any parameters are shown in lower case. A parameter shown in
[square brackets] is optional. For example, [GMT] indicates [square brackets] is optional. For example, [GMT] indicates
that the triglyph GMT may present or omitted. A parameter that that the triglyph GMT may be present or omitted. A parameter
may be repeated is followed by an ellipsis. Mutually exclusive that may be repeated is followed by an ellipsis. Mutually
parameters are separated by a vertical bar (|) character. For exclusive parameters are separated by a vertical bar (|)
example, ggg|<message-id> indicates that a group name or a character. For example, ggg|<message-id> indicates that a
<message-id> may be specified, but not both. Some parameters group name or a <message-id> may be specified, but not both.
may be case or language specific. See RFC 1036[6] for these Some parameters may be case or language specific. See RFC
details. 1036[6] for these details.
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In addition, certain commands make use of a pattern for In addition, certain commands make use of a pattern for
selection of multiple news groups. The pattern in all cases is selection of multiple news groups. The pattern in all cases is
based on the WILDMAT format introduced by Rich Salz in 1986. based on the WILDMAT format introduced by Rich Salz in 1986.
Arguments expected to be in wildmat format will be represented Arguments expected to be in wildmat format will be represented
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by the string wildmat. This format is discussed in detail in by the string wildmat. This format is discussed in detail in
section 5 of this memo. section 5 of this memo.
7. The GREETING Step 7. The GREETING Step
7.1 Initial Connection 7.1 Initial Connection
There is no keyword presented by the client upon initial There is no keyword presented by the client upon initial
connection to the server. The server MUST present an connection to the server. The server MUST present an
appropriate response code as a greeting to the client. This appropriate response code as a greeting to the client. This
response informs the client about what steps the client should response informs the client about what steps the client should
take to reach the news exchange step. take to reach the news exchange step.
The server must present a 200 greeting code if the client is The server must present a 200 greeting code if the client is
authorized to post articles though the use of the POST keyword authorized to post articles though the use of the POST keyword
on this server. on this server.
The server must present a 201 greeting code if the client is The server must present a 201 greeting code if the client is
not authorized to post articles using the POST keyword, but no not authorized to post articles using the POST keyword.
other authentication is required.
The server must present a 205 greeting code if the client is
required to present authentication before it is permitted to
use any keywords available in the news exchange step.
The server must present a 502 greeting code if the client is The server must present a 502 greeting code if the client is
not permitted under any circumstances from interacting with not permitted under any circumstances from interacting with
the server. The server should immediately close the connection the server. The server should immediately close the connection
with the client after presenting this code. with the client after presenting this code.
In all other cases, the server must present a 400 greeting In all other cases, the server must present a 400 greeting
code. code.
7.1.1 MODE READER 7.1.1 MODE READER
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MODE READER MAY be used by the client to indicate to the MODE READER MAY be used by the client to indicate to the
server that it is a news reading client. This command may be server that it is a news reading client. This command may be
entered at any time. The server must present a greeting code entered at any time. The server must present a greeting code
(as described in section 7.1.1.1) appropriate to the server's (as described in section 7.1.1.1) appropriate to the server's
ability to provide service to this client in this mode. ability to provide service to this client in this mode.
7.1.1.1 Responses 7.1.1.1 Responses
200 Hello, you can post 200 Hello, you can post
201 Hello, you can't post 201 Hello, you can't post
205 Authentication required
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400 Service temporarily unavailable 400 Service temporarily unavailable
502 Service unavailable 502 Service unavailable
8. The CAPABILITIES DISCOVERY Step 8. The CAPABILITIES DISCOVERY Step
A client NNTP supporting NNTP service extensions should query A client NNTP supporting NNTP service extensions should query
a server early in the session for extensions session by a server early in the session for extensions session by
issuing the LIST EXTENSIONS command. If the NNTP server issuing the LIST EXTENSIONS command. If the NNTP server
supports the NNTP service extensions it MUST give a successful supports the NNTP service extensions it MUST give a successful
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response (see section 8.1.1), a failure response (see section response (see section 8.1.1), a failure response (see section
8.1.2), or an error response (see section 8.1.3). If the NNTP 8.1.2), or an error response (see section 8.1.3). If the NNTP
server does not support any NNTP service extensions, it MUST server does not support any NNTP service extensions, it MUST
generate an error response (see section 8.1.4). generate an error response (see section 8.1.4).
8.1 LIST EXTENSIONS 8.1 LIST EXTENSIONS
If successful, the server NNTP MUST respond with code 202. On If successful, the server NNTP MUST respond with code 202. On
failure, the server NNTP MUST respond with code 503. On error, failure, the server NNTP MUST respond with code 503. On error,
the server NNTP MUST respond with one of codes 400, 402, 500 the server NNTP MUST respond with one of codes 400, 402, 500,
and 501. 501 and 502.
This command MAY be issued at anytime during a session. It is This command MAY be issued at anytime during a session. It is
not required that the client issues this command before not required that the client issues this command before
attempting to make use of any extension. The response attempting to make use of any extension. The response
generated by this command MAY change during a session because generated by this command MAY change during a session because
of other state information (e.g. authentication or server of other state information (e.g. server administration).
administration). However, a client NNTP MUST NOT cache (for However, a client NNTP MUST NOT cache (for use in another
use in another session) any information returned if the LIST session) any information returned if the LIST EXTENSIONS
EXTENSIONS command succeeds. That is, a client NNTP MUST issue command succeeds. That is, a client NNTP MUST issue the LIST
the LIST EXTENSIONS command at least once during each session EXTENSIONS command at least once during each session to get
to get the current and correct information concerning the current and correct information concerning available
available extensions during that session. extensions during that session.
8.1.1 Successful response 8.1.1 Successful response
If the server NNTP implements and is able to perform the LIST If the server NNTP implements and is able to perform the LIST
EXTENSIONS command, it MUST return code 202. EXTENSIONS command, it MUST return code 202.
Text following the return code on the first line of the reply Text following the return code on the first line of the reply
is free form, and not interpreted, and has no practical use, is free form, and not interpreted, and has no practical use,
as this text is not expected to be revealed to end users. The as this text is not expected to be revealed to end users. The
syntax of other reply lines is precisely defined, and if syntax of other reply lines is precisely defined, and if
present, MUST be exactly as specified. present, MUST be exactly as specified.
Each line listing an extension in the extension-listing begins Each line listing an extension in the extension-listing begins
with a single space. That space is not optional, nor does it with a single space. That space is not optional, nor does it
indicate general white space. This space guarantees that the indicate general white space. This space guarantees that the
line can never be misinterpreted as the end of the extension- line can never be misinterpreted as the end of the extension-
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listing, but is required even where there is no possibility of listing, but is required even where there is no possibility of
ambiguity. ambiguity.
Each extension supported must be listed on a separate line to Each extension supported must be listed on a separate line to
facilitate the possible inclusion of parameters supported by facilitate the possible inclusion of parameters supported by
each extension command. The extension-label to be used in the each extension command. The extension-label to be used in the
response to the LIST EXTENSIONS command will be specified as response to the LIST EXTENSIONS command will be specified as
each new extension is added to the NNTP command set. Often it each new extension is added to the NNTP command set. Often it
will be the name of a new command added; however this is not will be the name of a new command added; however this is not
required. In fact it is not required that a new feature required. In fact it is not required that a new feature
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actually add a new command. Any parameters included are to be actually add a new command. Any parameters included are to be
specified with the definition of the command concerned. specified with the definition of the command concerned.
That specification shall also specify how any parameters That specification shall also specify how any parameters
present are to be interpreted. present are to be interpreted.
The extension-label is nominally case sensitive, however the The extension-label is nominally case sensitive, however the
definitions of specific labels and parameters specify the definitions of specific labels and parameters specify the
precise interpretation, and it is to be expected that those precise interpretation, and it is to be expected that those
definitions will usually specify the label in a case definitions will usually specify the label in a case
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A typical example reply to the LIST EXTENSIONS command might A typical example reply to the LIST EXTENSIONS command might
be a multiline reply of the form: be a multiline reply of the form:
[C] LIST EXTENSIONS [C] LIST EXTENSIONS
[S] 202-Extensions supported: [S] 202-Extensions supported:
[S] OVER [S] OVER
[S] AUTHINFO-GENERIC
[S] PAT [S] PAT
[S] LISTGROUP [S] LISTGROUP
[S] AUTHINFO
[S] . [S] .
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The particular extensions shown here are simply examples of The particular extensions shown here are simply examples of
what may be defined in other places, no particular meaning what may be defined in other places, no particular meaning
should be attributed to them. Recall also, that the extension should be attributed to them. Recall also, that the extension
names returned are not command names, as such, but simply names returned are not command names, as such, but simply
indications that the server possesses some attribute or other. indications that the server possesses some attribute or other.
The order in which the extensions are returned is of no The order in which the extensions are returned is of no
importance, NNTP Servers processes are not required to importance, NNTP Servers processes are not required to
implement any particular order, or even to consistently return implement any particular order, or even to consistently return
the same order when the command is repeated. the same order when the command is repeated.
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8.1.2 Failure response 8.1.2 Failure response
If for some reason the server NNTP is unable to list the If for some reason the server NNTP is unable to list the
service extensions it supports, it MUST return code 503. service extensions it supports, it MUST return code 503.
In the case of a failure response, the client NNTP may try the In the case of a failure response, the client NNTP may try the
extensions either as the need arises or configure itself for extensions either as the need arises or configure itself for
the basic NNTP functionality defined in this document. the basic NNTP functionality defined in this document.
8.1.3 Error responses from extended servers 8.1.3 Error responses from extended servers
If the server NNTP recognizes the LIST EXTENSIONS command, but If the server NNTP recognizes the LIST EXTENSIONS command, but
due to various conditions cannot make any extensions available due to various conditions cannot make any extensions available
to the client at the time the client issued the LIST to the client at the time the client issued the LIST
EXTENSIONS command, it MUST return code 402. No list (even an EXTENSIONS command, it MUST return code 402. No list (not even
empty one) will be returned. an empty one) will be returned.
The client NNTP should configure itself for the basic NNTP The client NNTP should configure itself for the basic NNTP
functionality defined in this document, or issue commands that functionality defined in this document, or issue commands that
might change the state of the server (authentication, for might change the state of the server, or issue the QUIT
example), or issue the QUIT command (see section 11.1) if a command (see section 10.1) if a particular extension is
particular extension is required for the client to properly required for the client to properly operate.
operate.
If the server NNTP determines that the NNTP service is no If the server NNTP determines that the NNTP service is no
longer available (e.g., due to imminent system shutdown), it longer available (e.g., due to imminent system shutdown), it
must return code 400. must return code 400. Note that this is response code should
not be generated due to an inactivity timeout as described in
section 4.
In the case of an error response, the client NNTP should issue In the case of an error response, the client NNTP should issue
the QUIT command (see section 11.1). the QUIT command (see section 10.1).
8.1.4 Responses from servers without extensions 8.1.4 Responses from servers without extensions
A server NNTP that conforms to this memo but does not support A server NNTP that conforms to this memo but does not support
the extensions specified here will not recognize the LIST the extensions specified here will not recognize the LIST
EXTENSIONS command and MUST consequently return code 500 or EXTENSIONS command and MUST consequently return code 500 or
code 501. The server NNTP SHALL stay in the same state after code 501. The server NNTP SHALL stay in the same state after
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returning this code. The client NNTP may try the extensions returning this code. The client NNTP may try the extensions
either as the need arises or configure itself for the basic either as the need arises or configure itself for the basic
NNTP functionality defined in this document. NNTP functionality defined in this document.
8.1.5 Responses from improperly implemented servers 8.1.5 Responses from improperly implemented servers
A server NNTP that improperly implements the LIST EXTENSIONS A server NNTP that improperly implements the LIST EXTENSIONS
command may return an empty list. Clients SHALL accommodate command may return an empty list. Clients SHALL accommodate
this protocol violation and interpret it as a response code this protocol violation and interpret it as a response code
402. 402.
9. The AUTHENTICATION Step Barber [Page 10]
9. The NEWS EXCHANGE Step
9.1 AUTHINFO
AUTHINFO is used to inform a server about the identity of a
user of the server. In all cases, clients MUST provide this
information when requested by the server. Servers are not
required to accept authentication information that is
volunteered by the client. Clients MUST accommodate servers
that reject any authentication information volunteered by the
client.
9.1.1 AUTHINFO
AUTHINFO USER username
AUTHINFO PASS password
When authorization is required, the server MUST send a 450
response requesting authorization from the client. The client
MUST enter AUTHINFO USER username in order to make use of the
AUTHINFO authentication step. If the server will accept this
form of authentication and a password is required to complete
the authentication step, the server MUST respond with a 350
response. The client MUST then send AUTHINFO PASS followed by
one or more space characters followed by the password. If the
username/password combination is valid or no password is
required, the server MUST return a 250 response and the client
should then retry the original command to which the server
responded with the 450 response. The server SHALL then process
the command normally. If the combination is not valid, the
server MUST return a 452 response.
If the server returns 501, this means that the authenticator
invocation was syntactically incorrect, or that this form of
AUTHINFO is not supported.
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If the requested authenticator capability is not found or
there is some other unspecified server program error, the
server MUST return the 503 response code.
9.1.1.1 Responses
250 Authorization accepted
350 Continue with authorization sequence
450 Authorization required for this command
452 Authorization rejected
501 Command not supported or Command Syntax Error
503 Program error, function not performed
9.1.2 AUTHINFO GENERIC
AUTHINFO GENERIC authenticator arguments...
AUTHINFO GENERIC is used to identify a specific entity to the
server using arbitrary authentication or identification
protocols. The desired protocol is indicated by the
authenticator parameter, and any number of parameters can be
passed to the authenticator.
When authorization is required, the server will send a 450
response requesting authorization from the client.
The client should enter AUTHINFO GENERIC followed by the
authenticator name and the arguments if any. The
authenticator and arguments must not contain the sequence
"..".
The server will attempt to engage the server end
authenticator; similarly, the client should engage the client
end authenticator. The server end authenticator will then
initiate authentication using the NNTP sockets (if appropriate
for that authentication protocol), using the protocol
specified by the authenticator name. These authentication
protocols are not included in this document, but are similar
in structure to those referenced in RFC 1731[7] for the IMAP-4
protocol.
If the server returns 501, this means that the authenticator
invocation was syntactically incorrect, or that AUTHINFO
GENERIC is not supported. The client should retry using the
AUTHINFO USER command.
If the requested authenticator capability is not found or
there is some other unspecified server program error, the
server returns the 503 response code.
The authenticators converse using their protocol until
complete. If the authentication succeeds, the server
authenticator will terminate with a 250, and the client can
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continue by reissuing the command that prompted the 350. If
the authentication fails, the server will respond with a 452.
The client must provide authentication when requested by the
server. The server may request authentication at any time.
Servers may request authentication more than once during a
single session.
When the server authenticator completes, it provides to the
server (by a mechanism herein undefined) the email address of
the user, and potentially what the user is allowed to access.
Once authenticated and if the email address provided by the
authenticator does not match the user-supplied From: line, the
server SHALL insert a Sender: line into any posted articles
using the email address provided by the authenticator.
Additionally, the server should log the event, including the
user's authenticated email address (if available). This will
provide a means by which subsequent statistics generation can
associate news group references with unique entities - not
necessarily by name.
9.1.2.1 Responses
250 Authorization accepted
450 Authorization required for this command
452 Authorization rejected
501 Command not supported or Command Syntax Error
503 Program error, function not performed
nnn authenticator-specific protocol.
9.1.3 Transition Issues
The implementations of AUTHINFO commonly in use prior to the
release of this memo have a different response code set. The
code 281 was used in place of 250, 381 and 480 were used in
place of 450 and 482 and 502 were used in place of 452. Client
coded to be compliant with this spec may also want to be able
to accommodate the older codes to lessen the impact of the
transition to this specification.
10. The NEWS EXCHANGE Step
During this step, two basic types of transactions occur: During this step, two basic types of transactions occur:
article retrieval from the server and article posting to the article retrieval from the server and article posting to the
server. server.
10.1 Article Retrieval 9.1 Article Retrieval
News reading clients have available a variety of mechanisms to News reading clients have available a variety of mechanisms to
retrieve articles via NNTP. The news articles are stored and retrieve articles via NNTP. The news articles are stored and
indexed using three types of keys. One key is the message id indexed using three types of keys. One key is the message id
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of an article. According to RFC 1036, this identifier should of an article. According to RFC 1036, this identifier should
be globally unique. Another key is composed of the news group be globally unique. Another key is composed of the news group
name and the article number within that news group. That key name and the article number within that news group. That key
MUST be unique to a particular server (there will be only one MUST be unique to a particular server (there will be only one
article with that number within a particular news group), but article with that number within a particular news group), but
is not required to be globally unique. Additionally, because is not required to be globally unique. Additionally, because
the same article can be cross-posted to multiple news groups, the same article can be cross-posted to multiple news groups,
there may be multiple keys that point to the same article on there may be multiple keys that point to the same article on
the same server. The final key is the arrival timestamp, the same server. The final key is the arrival timestamp,
giving the time that the article arrived at the server. giving the time that the article arrived at the server.
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Article numbers MUST lie between 1 and 4,294,967,295 Article numbers MUST lie between 1 and 4,294,967,295
inclusive. The client and server SHOULD NOT use leading zeroes inclusive. The client and server SHOULD NOT use leading zeroes
in specifying article numbers, and MUST NOT use more than 16 in specifying article numbers, and MUST NOT use more than 16
digits. In some situations, the value zero replaces an article digits. In some situations, the value zero replaces an article
number to show some special situation. One case involves number to show some special situation. One case involves
responses to the ARTICLE, STAT, BODY and HEAD commands where a responses to the ARTICLE, STAT, BODY and HEAD commands where a
<message-id> is specified as the argument. In those cases, the <message-id> is specified as the argument. In those cases, the
"current article pointer" is not changed. "current article pointer" is not changed.
10.1.1 Article Retrieval by News Group Name and Article Number 9.1.1 Article Retrieval by News Group Name and Article Number
The following commands are used to set the current news group The following commands are used to set the current news group
name and the "current article pointer" which is used by other name and the "current article pointer" which is used by other
commands for article retrieval. commands for article retrieval.
10.1.1.1 GROUP 9.1.1.1 GROUP
GROUP ggg GROUP ggg
The required parameter ggg is the name of the news group to be The required parameter ggg is the name of the news group to be
selected (e.g. "news.software.b"). A list of valid news groups selected (e.g. "news.software.b"). A list of valid news groups
may be obtained by using the LIST keyword. See section 10.4
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may be obtained by using the LIST keyword. See section 9.4
for more information on the LIST keyword. for more information on the LIST keyword.
The successful selection response will return the article The successful selection response will return the article
numbers of the first and last articles in the group at the numbers of the first and last articles in the group at the
moment of selection (these numbers are referred to as the moment of selection (these numbers are referred to as the
"reported low water mark" and the "reported high water mark"), "reported low water mark" and the "reported high water mark"),
and an estimate of the number of articles on file in the and an estimate of the number of articles on file in the
group. group.
If the group is not empty, the estimate MUST be at least the If the group is not empty, the estimate MUST be at least the
actual number of articles available, and MUST be no greater actual number of articles available, and MUST be no greater
than one more than the difference between the reported low and than one more than the difference between the reported low and
high water marks. (Some implementations will actually count high water marks. (Some implementations will actually count
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the number of articles on file. Others will just subtract the the number of articles on file. Others will just subtract the
low water mark from the high water mark and add one to get an low water mark from the high water mark and add one to get an
estimate.) estimate.)
If the group is empty, one of the following three situations If the group is empty, one of the following three situations
will occur. Clients MUST accept all three cases; servers MUST will occur. Clients MUST accept all three cases; servers MUST
NOT represent an empty group in any other way. NOT represent an empty group in any other way.
. The high water mark will be one less than the low water mark, . The high water mark will be one less than the low water mark,
and the estimated article count will be zero. Servers SHOULD and the estimated article count will be zero. Servers SHOULD
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will not have the number one greater than the reported high will not have the number one greater than the reported high
water mark). water mark).
Except when the group is empty and all three numbers are zero, Except when the group is empty and all three numbers are zero,
whenever a subsequent GROUP command for the same news group is whenever a subsequent GROUP command for the same news group is
issued, either by the same client or a different client, the issued, either by the same client or a different client, the
reported low water mark in the response MUST be no less than reported low water mark in the response MUST be no less than
that in any previous response for that news group sent to any that in any previous response for that news group sent to any
client. The client may make use of the low water mark to client. The client may make use of the low water mark to
remove all remembered information about articles with lower remove all remembered information about articles with lower
numbers, as these will never recur. This includes the numbers, as these will never recur. This includes the
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situation when the high water mark is one less than the low situation when the high water mark is one less than the low
water mark. water mark.
No similar assumption can be made about the high water mark, No similar assumption can be made about the high water mark,
as this can decrease if an article is removed, and then as this can decrease if an article is removed, and then
increase again if it is reinstated or if new articles arrive. increase again if it is reinstated or if new articles arrive.
When a valid group is selected by means of this command, the When a valid group is selected by means of this command, the
internally maintained "current article pointer" MUST be set to internally maintained "current article pointer" MUST be set to
the first article in the group and the name of the current the first article in the group and the name of the current
news group MUST be set to the selected news group name. If an news group MUST be set to the selected news group name. If an
invalid group is specified, the previously selected group and invalid group is specified, the previously selected group and
article MUST remain selected. If an empty news group is article MUST remain selected. If an empty news group is
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selected, the "current article pointer" is in an indeterminate selected, the "current article pointer" is in an indeterminate
state and MUST NOT be used. state and MUST NOT be used.
The GROUP keyword MUST be used by a client and a successful The GROUP keyword MUST be used by a client and a successful
response received before the any other command is used that response received before the any other command is used that
depends on having the "current article pointer" be valid. depends on having the "current article pointer" be valid.
10.1.1.1.1 Responses 9.1.1.1.1 Responses
211 n f l s group selected 211 n f l s group selected
(n = estimated number of articles in group, f = first (n = estimated number of articles in group, f = first
article number in the group, l = last article number in article number in the group, l = last article number in
the group, s = name of the group.) the group, s = name of the group.)
411 no such news group 411 no such news group
10.1.1.2 LAST 9.1.1.2 LAST
LAST LAST
The internally maintained "current article pointer" MUST be The internally maintained "current article pointer" MUST be
set to the previous article in the current news group. If set to the previous article in the current news group. If
already positioned at the first article of the news group, an already positioned at the first article of the news group, an
error message MUST be returned and the current article MUST error message MUST be returned and the current article MUST
remain selected. remain selected.
There MAY be no previous article in the group, although the There MAY be no previous article in the group, although the
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There MUST NOT be a previous article when the current article There MUST NOT be a previous article when the current article
number is the reported low water mark. number is the reported low water mark.
Because articles can be removed and added, the results of Because articles can be removed and added, the results of
multiple LAST and NEXT commands MAY not be consistent over the multiple LAST and NEXT commands MAY not be consistent over the
life of a particular NNTP session. life of a particular NNTP session.
The internally-maintained "current article pointer" MUST be The internally-maintained "current article pointer" MUST be
set by this command. set by this command.
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A response indicating the current article number and a A response indicating the current article number and a
message-id string MUST be returned. No text is sent in message-id string MUST be returned. No text is sent in
response to this command. response to this command.
10.1.1.2.1 Responses 9.1.1.2.1 Responses
223 n a article retrieved - request text separately (n = 223 n a article retrieved - request text separately (n =
article number, a = unique article id) article number, a = unique article id)
412 no news group selected 412 no news group selected
420 no current article has been selected 420 no current article has been selected
422 no previous article in this group 422 no previous article in this group
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10.1.1.3 NEXT
NEXT NEXT
The internally maintained "current article pointer" MUST be The internally maintained "current article pointer" MUST be
advanced to the next article in the current news group. If no advanced to the next article in the current news group. If no
more articles remain in the current group, an error message more articles remain in the current group, an error message
MUST be returned and the current article MUST remain selected. MUST be returned and the current article MUST remain selected.
The internally-maintained "current article pointer" MUST be The internally-maintained "current article pointer" MUST be
set by this command. set by this command.
A response indicating the current article number and the A response indicating the current article number and the
message-id string MUST be returned. No text is sent in message-id string MUST be returned. No text is sent in
response to this command. response to this command.
10.1.1.3.1 Responses 9.1.1.3.1 Responses
223 n a article retrieved - request text separately (n = 223 n a article retrieved - request text separately (n =
article number, a = unique article id) article number, a = unique article id)
412 no news group selected 412 no news group selected
420 no current article has been selected 420 no current article has been selected
421 no next article in this group 421 no next article in this group
10.2 Retrieval of Articles and Article Sections 9.2 Retrieval of Articles and Article Sections
There are two forms to the ARTICLE command (and the related There are two forms to the ARTICLE command (and the related
BODY, HEAD, and STAT commands), each using a different method BODY, HEAD, and STAT commands), each using a different method
of specifying which article is to be retrieved. When the of specifying which article is to be retrieved. When the
ARTICLE keyword is followed by a message-id in angle brackets ARTICLE keyword is followed by a message-id in angle brackets
("<" and ">"), the first form of the command MUST be used; ("<" and ">"), the first form of the command MUST be used;
when a numeric parameter or no parameter is supplied, the when a numeric parameter or no parameter is supplied, the
second form MUST be invoked. In the cases where the argument second form MUST be invoked. In the cases where the argument
is a message-id, the article number specified in the response is a message-id, the article number specified in the response
must be zero. This is one of the special cases described in must be zero. This is one of the special cases described in
section 10.1. section 9.1.
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An article, as defined by RFC 1036, consists of two parts: the An article, as defined by RFC 1036, consists of two parts: the
article headers and the article body. When responding to an article headers and the article body. When responding to an
article command, the server returns the entire article article command, the server returns the entire article
contents and does not attempt to alter or translate them in contents and does not attempt to alter or translate them in
any way. any way.
10.2.1 ARTICLE 9.2.1 ARTICLE
ARTICLE [<message-id>|nnn] ARTICLE [<message-id>|nnn]
This response displays the header, a blank line, then the body This response displays the header, a blank line, then the body
(text) of the specified article. The optional parameter nnn is (text) of the specified article. The optional parameter nnn is
the numeric id of an article in the current news group and the numeric id of an article in the current news group and
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SHOULD be chosen from the range of articles provided when the SHOULD be chosen from the range of articles provided when the
news group was selected. If it is omitted, the current news group was selected. If it is omitted, the current
article is assumed. Message-id is the message id of an article article is assumed. Message-id is the message id of an article
as shown in that article's header. as shown in that article's header.
Please note that the internally-maintained "current article Please note that the internally-maintained "current article
pointer" MUST NOT be altered when the message-id argument is pointer" MUST NOT be altered when the message-id argument is
used. This is both to facilitate the presentation of articles used. This is both to facilitate the presentation of articles
that may be referenced within an article being read, and that may be referenced within an article being read, and
because of the semantic difficulties of determining the proper because of the semantic difficulties of determining the proper
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The message-id string returned is an identification string The message-id string returned is an identification string
contained within angle brackets ("<" and ">"), which is contained within angle brackets ("<" and ">"), which is
derived from the header of the article itself. The Message-ID derived from the header of the article itself. The Message-ID
header line (required by RFC 1036) from the article must be header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line used to supply this information. If the message-id header line
is missing from the article, a single digit "0" (zero) should is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets. be supplied within the angle brackets.
Since the message-id field is unique for each article, it may Since the message-id field is unique for each article, it may
be used by a news reading program to skip duplicate displays be used by a news reading program to skip duplicate displays
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of articles that have been posted more than once, or to more of articles that have been posted more than once, or to more
than one news group. than one news group.
10.2.1.1 Responses 9.2.1.1 Responses
220 n <a> article retrieved - head and body follow (n = 220 n <a> article retrieved - head and body follow (n =
article number, <a> = message-id) article number, <a> = message-id)
412 no news group has been selected 412 no news group has been selected
420 no current article has been selected 420 no current article has been selected
423 no such article number in this group 423 no such article number in this group
430 no such article found 430 no such article found
10.2.2 HEAD 9.2.2 HEAD
HEAD [<message-id>|nnn] HEAD [<message-id>|nnn]
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This response displays the header of the specified article. This response displays the header of the specified article.
The optional parameter nnn is the numeric id of an article in The optional parameter nnn is the numeric id of an article in
the current news group and SHOULD be chosen from the range of the current news group and SHOULD be chosen from the range of
articles provided when the news group was selected. If it is articles provided when the news group was selected. If it is
omitted, the current article is assumed. Message-id is the omitted, the current article is assumed. Message-id is the
message id of an article as shown in that article's header. message id of an article as shown in that article's header.
Please note that the internally-maintained "current article Please note that the internally-maintained "current article
pointer" MUST NOT be altered when the message-id argument is pointer" MUST NOT be altered when the message-id argument is
used. This is both to facilitate the presentation of articles used. This is both to facilitate the presentation of articles
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string, and that text is to follow MUST be returned. string, and that text is to follow MUST be returned.
The message-id string returned is an identification string The message-id string returned is an identification string
contained within angle brackets ("<" and ">"), which is contained within angle brackets ("<" and ">"), which is
derived from the header of the article itself. The Message-ID derived from the header of the article itself. The Message-ID
header line (required by RFC 1036) from the article must be header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line used to supply this information. If the message-id header line
is missing from the article, a single digit "0" (zero) should is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets. be supplied within the angle brackets.
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Since the message-id field is unique for each article, it may Since the message-id field is unique for each article, it may
be used by a news reading program to skip duplicate displays be used by a news reading program to skip duplicate displays
of articles that have been posted more than once, or to more of articles that have been posted more than once, or to more
than one news group. than one news group.
10.2.2.1 Responses 9.2.2.1 Responses
221 n <a> article retrieved - head follows 221 n <a> article retrieved - head follows
412 no news group has been selected 412 no news group has been selected
420 no current article has been selected 420 no current article has been selected
423 no such article number in this group 423 no such article number in this group
430 no such article found 430 no such article found
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10.2.3 BODY
BODY [<message-id>|nnn] BODY [<message-id>|nnn]
This response displays the body (text) of the specified This response displays the body (text) of the specified
article. The optional parameter nnn is the numeric id of an article. The optional parameter nnn is the numeric id of an
article in the current news group and SHOULD be chosen from article in the current news group and SHOULD be chosen from
the range of articles provided when the news group was the range of articles provided when the news group was
selected. If it is omitted, the current article is assumed. selected. If it is omitted, the current article is assumed.
Message-id is the message id of an article as shown in that Message-id is the message id of an article as shown in that
article's header. article's header.
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If there is a valid article to present in a reply to this If there is a valid article to present in a reply to this
command, a response indicating the current article number (or command, a response indicating the current article number (or
zero when the message-id argument is used), a message-id zero when the message-id argument is used), a message-id
string, and that text is to follow MUST be returned. string, and that text is to follow MUST be returned.
The message-id string returned is an identification string The message-id string returned is an identification string
contained within angle brackets ("<" and ">"), which is contained within angle brackets ("<" and ">"), which is
derived from the header of the article itself. The Message-ID derived from the header of the article itself. The Message-ID
header line (required by RFC 1036) from the article must be header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line used to supply this information. If the message-id header line
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is missing from the article, a single digit "0" (zero) should is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets. be supplied within the angle brackets.
Since the message-id field is unique for each article, it may Since the message-id field is unique for each article, it may
be used by a news reading program to skip duplicate displays be used by a news reading program to skip duplicate displays
of articles that have been posted more than once, or to more of articles that have been posted more than once, or to more
than one news group. than one news group.
10.2.3.1 Responses 9.2.3.1 Responses
222 n <a> article retrieved - body follows 222 n <a> article retrieved - body follows
412 no news group has been selected 412 no news group has been selected
420 no current article has been selected 420 no current article has been selected
423 no such article number in this group 423 no such article number in this group
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430 no such article found 430 no such article found
10.2.4 STAT 9.2.4 STAT
STAT [<message-id>|nnn] STAT [<message-id>|nnn]
This response returns only status information; no article This response returns only status information; no article
contents are returned. The optional parameter nnn is the contents are returned. The optional parameter nnn is the
numeric id of an article in the current news group and SHOULD numeric id of an article in the current news group and SHOULD
be chosen from the range of articles provided when the news be chosen from the range of articles provided when the news
group was selected. If it is omitted, the current article is group was selected. If it is omitted, the current article is
assumed. Message-id is the message id of an article as shown assumed. Message-id is the message id of an article as shown
in that article's header. in that article's header.
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mark for that group. mark for that group.
If there is a valid article to present in a reply to this If there is a valid article to present in a reply to this
command, a response indicating the current article number (or command, a response indicating the current article number (or
zero when the message-id argument is used) and a message-id zero when the message-id argument is used) and a message-id
string MUST be returned. string MUST be returned.
The message-id string returned is an identification string The message-id string returned is an identification string
contained within angle brackets ("<" and ">"), which is contained within angle brackets ("<" and ">"), which is
derived from the header of the article itself. The Message-ID derived from the header of the article itself. The Message-ID
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header line (required by RFC 1036) from the article must be header line (required by RFC 1036) from the article must be
used to supply this information. If the message-id header line used to supply this information. If the message-id header line
is missing from the article, a single digit "0" (zero) should is missing from the article, a single digit "0" (zero) should
be supplied within the angle brackets. be supplied within the angle brackets.
Since the message-id field is unique for each article, it may Since the message-id field is unique for each article, it may
be used by a news reading program to skip duplicate displays be used by a news reading program to skip duplicate displays
of articles that have been posted more than once, or to more of articles that have been posted more than once, or to more
than one news group. than one news group.
10.2.4.1 Responses 9.2.4.1 Responses
223 n <a> article retrieved - request text separately 223 n <a> article retrieved - request text separately
412 no news group has been selected 412 no news group has been selected
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420 no current article has been selected 420 no current article has been selected
423 no such article number in this group 423 no such article number in this group
430 no such article found 430 no such article found
10.3 Article Posting 9.3 Article Posting
Article posting is done in one of two modes: individual Article posting is done in one of two modes: individual
article posting from news reading clients and article transfer article posting from news reading clients and article transfer
from other news servers. from other news servers.
10.3.1 POST 9.3.1 POST
POST POST
If posting is allowed, response code 340 MUST be returned to If posting is allowed, response code 340 MUST be returned to
indicate that the article to be posted should be sent. indicate that the article to be posted should be sent.
Response code 440 MUST be sent if that posting is prohibited Response code 440 MUST be sent if that posting is prohibited
for some installation-dependent reason. for some installation-dependent reason.
If posting is permitted, the article MUST be presented to the If posting is permitted, the article MUST be presented to the
server by the client in the format specified by RFC 1036. The server by the client in the format specified by RFC 1036. The
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Following the presentation of the termination sequence by the Following the presentation of the termination sequence by the
client, the server MUST return a response code indicating client, the server MUST return a response code indicating
success or failure of the article transfer. success or failure of the article transfer.
No attempt shall be made by the server to filter characters, No attempt shall be made by the server to filter characters,
fold or limit lines, or otherwise process incoming text. The fold or limit lines, or otherwise process incoming text. The
intent is that the server just passes the incoming message to intent is that the server just passes the incoming message to
be posted to the server installation's news posting software, be posted to the server installation's news posting software,
which is not part of this specification. which is not part of this specification.
10.3.1.1 Responses Barber [Page 19]
9.3.1.1 Responses
240 article received ok 240 article received ok
340 send article to be posted. End with <CR-LF>.<CR-LF> 340 send article to be posted. End with <CR-LF>.<CR-LF>
440 posting not allowed 440 posting not allowed
441 posting failed 441 posting failed
10.3.2 IHAVE 9.3.2 IHAVE
IHAVE <message-id> IHAVE <message-id>
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The IHAVE command informs the server that the client has an The IHAVE command informs the server that the client has an
article whose id is <message-id>. If the server desires a copy article whose id is <message-id>. If the server desires a copy
of that article, it MUST return a response instructing the of that article, it MUST return a response instructing the
client to send the entire article. If the server does not want client to send the entire article. If the server does not want
the article (if, for example, the server already has a copy of the article (if, for example, the server already has a copy of
it), a response indicating that the article is not wanted MUST it), a response indicating that the article is not wanted MUST
be returned. be returned.
If transmission of the article is requested, the client MUST If transmission of the article is requested, the client MUST
send the entire article, including header and body, in the send the entire article, including header and body, in the
skipping to change at line 1193 skipping to change at page 34, line ?
However, the server may elect not to post or forward the However, the server may elect not to post or forward the
article if after further examination of the article it deems article if after further examination of the article it deems
it inappropriate to do so. Reasons for such subsequent it inappropriate to do so. Reasons for such subsequent
rejection of an article may include such problems as rejection of an article may include such problems as
inappropriate news groups or distributions, disk space inappropriate news groups or distributions, disk space
limitations, article lengths, garbled headers, and the like. limitations, article lengths, garbled headers, and the like.
These are typically restrictions enforced by the server host's These are typically restrictions enforced by the server host's
news software and not necessarily the NNTP server itself. news software and not necessarily the NNTP server itself.
10.3.2.1 Responses 9.3.2.1 Responses
235 article transferred ok 235 article transferred ok
335 send article to be transferred. End with <CR- 335 send article to be transferred. End with <CR-
LF>.<CR-LF> LF>.<CR-LF>
435 article not wanted - do not send it 435 article not wanted - do not send it
436 transfer failed - try again later 436 transfer failed - try again later
437 article rejected - do not try again 437 article rejected - do not try again
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Because some host news posting software may not be able to Because some host news posting software may not be able to
immediately render status on the whether an article is immediately render status on the whether an article is
inappropriate for posting or forwarding, an NNTP server MAY inappropriate for posting or forwarding, an NNTP server MAY
acknowledge the successful transfer of the article and later acknowledge the successful transfer of the article and later
silently discard it. Thus an NNTP server may return the 235 silently discard it. Thus an NNTP server may return the 235
acknowledgment code and later discard the received article. acknowledgment code and later discard the received article.
10.4 The LIST Keyword 9.4 The LIST Keyword
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10.4.1 LIST
LIST [ACTIVE [wildmat]] LIST [ACTIVE [wildmat]]
The response to the LIST keyword with no parameters returns a The response to the LIST keyword with no parameters returns a
list of valid news groups and associated information. Each list of valid news groups and associated information. Each
news group is sent as a line of text in the following format: news group is sent as a line of text in the following format:
group last first status group last first status
where <group> is the name of the news group, <last> is the where <group> is the name of the news group, <last> is the
skipping to change at line 1253 skipping to change at page 34, line ?
and therefore cannot be posted to; that is, articles posted to and therefore cannot be posted to; that is, articles posted to
them must be mailed to a moderator who will post them for the them must be mailed to a moderator who will post them for the
original poster. This is independent of the posting original poster. This is independent of the posting
permission granted to a client by the NNTP server. permission granted to a client by the NNTP server.
Please note that an empty list (i.e., the text body returned Please note that an empty list (i.e., the text body returned
by this command consists only of the terminating period) is a by this command consists only of the terminating period) is a
possible valid response, and indicates that there are possible valid response, and indicates that there are
currently no valid news groups. currently no valid news groups.
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If the optional matching parameter is specified, the list is If the optional matching parameter is specified, the list is
limited to only the groups that match the pattern. limited to only the groups that match the pattern.
Specifying a single group is usually very efficient for the Specifying a single group is usually very efficient for the
server, and multiple groups may be specified by using wildmat server, and multiple groups may be specified by using wildmat
patterns (described in section 5), not regular expressions. patterns (described in section 5), not regular expressions.
10.4.1.1 Responses 9.4.1.1 Responses
215 list of news groups follows 215 list of news groups follows
Barber [Page 24] 9.4.2 LIST ACTIVE.TIMES
10.4.2 LIST ACTIVE.TIMES
LIST ACTIVE.TIMES [wildmat] LIST ACTIVE.TIMES [wildmat]
The active.times file is maintained by some news transports The active.times file is maintained by some news transport
systems to contain information about the when and who created systems to contain information about when and who created a
a particular news group. The format of this file generally particular news group. The format of this file generally
includes three fields. The first field is the name of the news includes three fields. The first field is the name of the news
group. The second is the time when this group was created on group. The second is the time when this group was created on
this news server measured in seconds since January 1, 1970. this news server measured in seconds since January 1, 1970.
The third is the email address of the entity that created the The third is the email address of the entity that created the
news group. When executed, the information is displayed news group. When executed, the information is displayed
following the 215 response. When display is completed, the following the 215 response. When display is completed, the
server will send a period on a line by itself. If the server will send a period on a line by itself. If the
information is not available, the server will return the 503 information is not available, the server will return the 503
error response. error response.
If the optional matching parameter is specified, the list is If the optional matching parameter is specified, the list is
limited to only the groups that match the pattern. limited to only the groups that match the pattern.
Specifying a single group is usually very efficient for the Specifying a single group is usually very efficient for the
server, and multiple groups may be specified by using wildmat server, and multiple groups may be specified by using wildmat
patterns (described in section 5), not regular expression patterns (described in section 5), not regular expression
10.4.2.1 Responses 9.4.2.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
10.4.3 LIST DISTRIBUTIONS 9.4.3 LIST DISTRIBUTIONS
LIST DISTRIBUTIONS LIST DISTRIBUTIONS
The distributions file is maintained by some news transport The distributions file is maintained by some news transport
systems to contain information about valid values for the systems to contain information about valid values for the
Distribution: line in a news article header and about what the Distribution: line in a news article header and about what the
values mean. Each line contains two fields, the value and a values mean. Each line contains two fields, the value and a
short explanation on the meaning of the value. When executed, short explanation on the meaning of the value. When executed,
the information is displayed following the 215 response. When the information is displayed following the 215 response. When
display is completed, the server will send a period on a line display is completed, the server will send a period on a line
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by itself. If the information is not available, the server by itself. If the information is not available, the server
will return the 503 error response. will return the 503 error response.
10.4.3.1 Responses 9.4.3.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
10.4.4 LIST DISTRIB.PATS 9.4.4 LIST DISTRIB.PATS
LIST DISTRIB.PATS LIST DISTRIB.PATS
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The distrib.pats file is maintained by some news transport The distrib.pats file is maintained by some news transport
systems to contain default values for the Distribution: line systems to contain default values for the Distribution: line
in a news article header when posting to particular news in a news article header when posting to particular news
groups. This information could be used to provide a default groups. This information could be used to provide a default
value for the Distribution: line in the header when posting an value for the Distribution: line in the header when posting an
article. The information returned contains three fields article. The information returned contains three fields
separated by colons. The first column is a weight. The second separated by colons. The first column is a weight. The second
is a group name or a wildmat pattern that can be used to match is a group name or a wildmat pattern that can be used to match
a group name. The third is the value of the Distribution: a group name. The third is the value of the Distribution:
line that should be used when the group name matches and the line that should be used when the group name matches and the
weight value is the highest. All this processing is done by weight value is the highest. All this processing is done by
the news posting client and not by the server itself. The the news posting client and not by the server itself. The
server provides this information to the client for it to use server provides this information to the client for it to use
or ignore as it chooses. When executed, the information is or ignore as it chooses. When executed, the information is
displayed following the 215 response. When display is displayed following the 215 response. When display is
completed, the server will send a period on a line by itself. completed, the server will send a period on a line by itself.
If the information is not available, the server will return If the information is not available, the server will return
the 503 error response. the 503 error response.
10.4.4.1 Responses 9.4.4.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
10.4.5 LIST NEWSGROUPS 9.4.5 LIST NEWSGROUPS
LIST NEWSGROUPS [wildmat] LIST NEWSGROUPS [wildmat]
The newsgroups file is maintained by some news transport The newsgroups file is maintained by some news transport
systems to contain the name of each news group that is systems to contain the name of each news group that is
active on the server and a short description about the active on the server and a short description about the
purpose of each news group. Each line in the file contains purpose of each news group. Each line in the file contains
two fields, the news group name and a short explanation of two fields, the news group name and a short explanation of
the purpose of that news group. When executed, the the purpose of that news group. When executed, the
information is displayed following the 215 response. When information is displayed following the 215 response. When
display is completed, the server will send a period on a display is completed, the server will send a period on a
line by itself. If the information is not available, the line by itself. If the information is not available, the
server will return the 503 response. If the optional server will return the 503 response. If the optional
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matching parameter is specified, the list is limited to only matching parameter is specified, the list is limited to only
the groups that match the pattern (no matching is done on the groups that match the pattern (no matching is done on
the group descriptions). Specifying a single group is the group descriptions). Specifying a single group is
usually very efficient for the server, and multiple groups usually very efficient for the server, and multiple groups
may be specified by using wildmat patterns (see section 5), may be specified by using wildmat patterns (see section 5),
not regular expressions. If nothing is matched an empty list not regular expressions. If nothing is matched an empty list
is returned, not an error. is returned, not an error.
10.4.5.1 Responses 9.4.5.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
Barber [Page 26] 9.4.6 LIST OVERVIEW.FMT
10.4.6 LIST OVERVIEW.FMT
LIST OVERVIEW.FMT LIST OVERVIEW.FMT
The overview.fmt file is maintained by some news transport The overview.fmt file is maintained by some news transport
systems to contain the order in which header information is systems to contain the order in which header information is
stored in the overview databases for each news group. When stored in the overview databases for each news group. When
executed, news article header fields are displayed one line at executed, news article header fields are displayed one line at
a time in the order in which they are stored in the overview a time in the order in which they are stored in the overview
database[8] following the 215 response. When display is database[7] following the 215 response. When display is
completed, the server will send a period on a line by itself. completed, the server will send a period on a line by itself.
If the information is not available, the server will return If the information is not available, the server will return
the 503 response. the 503 response.
Please note that if the header has the word "full" (without Please note that if the header has the word "full" (without
quotes) after the colon, the header's name is prepended to its quotes) after the colon, the header's name is prepended to its
field in the output returned by the server. field in the output returned by the server.
10.4.6.1 Responses 9.4.6.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
10.4.7 LIST SUBSCRIPTIONS 9.4.7 LIST SUBSCRIPTIONS
LIST SUBSCRIPTIONS LIST SUBSCRIPTIONS
This command is used to get a default subscription list for This command is used to get a default subscription list for
new users of this server. The order of groups is significant. new users of this server. The order of groups is significant.
When this list is available, it is preceded by the 215 When this list is available, it is preceded by the 215
response and followed by a period on a line by itself. When response and followed by a period on a line by itself. When
this list is not available, the server returns a 503 response this list is not available, the server returns a 503 response
code. code.
10.4.7.1 Responses Barber [Page 24]
9.4.7.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
10.4.8 LISTGROUP 9.4.8 LISTGROUP
LISTGROUP [ggg] LISTGROUP [ggg]
The LISTGROUP command is used to get a listing of all the The LISTGROUP command is used to get a listing of all the
article numbers in a particular news group. article numbers in a particular news group.
The optional parameter ggg is the name of the news group to The optional parameter ggg is the name of the news group to
be selected (e.g. "news.software.b"). A list of valid news be selected (e.g. "news.software.b"). A list of valid news
groups may be obtained from the LIST command. If no group is groups may be obtained from the LIST command. If no group is
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specified, the current group is used as the default specified, the current group is used as the default
argument. argument.
The successful selection response will be a list of the The successful selection response will be a list of the
article numbers in the group followed by a period on a line article numbers in the group followed by a period on a line
by itself. by itself.
When a valid group is selected by means of this command, the When a valid group is selected by means of this command, the
internally maintained "current article pointer" MUST be set internally maintained "current article pointer" MUST be set
to the first article in the group. If an invalid group is to the first article in the group. If an invalid group is
specified, the previously selected group and article remain specified, the previously selected group and article remain
selected. If an empty news group is selected, the "current selected. If an empty news group is selected, the "current
article pointer" may be in an indeterminate state and should article pointer" may be in an indeterminate state and should
not be used. not be used.
The group name MUST match a news group obtained from the The group name MUST match a news group obtained from the
LIST command or an error will result, else the server will LIST command or an error will result, else the server will
response with the 411 error code. response with the 411 error code.
10.4.8.1 Responses 9.4.8.1 Responses
211 list of article numbers follow 211 list of article numbers follow
411 No such group 411 No such group
412 Not currently in news group 412 Not currently in news group
10.4.9 OVER 9.4.9 OVER
OVER [range] OVER [range]
The OVER command returns information from the overview The OVER command returns information from the overview
database for the article(s) specified. The information database for the article(s) specified. The information
returned in the response to this command can be used by returned in the response to this command can be used by
clients to follow discussion threads. clients to follow discussion threads.
The optional range argument may be any of the following: The optional range argument may be any of the following:
. an article number . an article number
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. an article number followed by a dash to indicate all following . an article number followed by a dash to indicate all following
. an article number followed by a dash followed by another . an article number followed by a dash followed by another
article number article number
If no argument is specified, then information from the current If no argument is specified, then information from the current
article is displayed. Successful responses start with a 224 article is displayed. Successful responses start with a 224
response followed by the overview information for all matched response followed by the overview information for all matched
messages. Once the output is complete, a period is sent on a messages. Once the output is complete, a period is sent on a
line by itself. If no argument is specified, the information line by itself. If no argument is specified, the information
for the current article is returned. A news group must have for the current article is returned. A news group must have
been selected earlier, else a 412 error response is returned. been selected earlier, else a 412 error response is returned.
If no articles are in the range specified, the server returns If no articles are in the range specified, the server returns
a 420 error response. A 502 response will be returned if the a 420 error response. A 502 response will be returned if the
client only has permission to transfer articles. client only has permission to transfer articles.
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Each line of output MUST be formatted with the article number, Each line of output MUST be formatted with the article number,
followed by each of the headers in the overview database or followed by each of the headers in the overview database or
the article itself (when the data is not available in the the article itself (when the data is not available in the
overview database) for that article separated by a US-ASCII overview database) for that article separated by a US-ASCII
tab character. The sequence of fields must be in this order: tab character. The sequence of fields must be in this order:
subject, author, date, message-id, references, byte count, and subject, author, date, message-id, references, byte count, and
line count. Other optional fields may follow line count. These line count. Other optional fields may follow line count. These
fields are specified by examining the response to the LIST fields are specified by examining the response to the LIST
OVERVIEW.FMT command. Where no data exists, a null field must OVERVIEW.FMT command. Where no data exists, a null field must
be provided (i.e. the output will have two tab characters be provided (i.e. the output will have two tab characters
adjacent to each other). Servers should not output fields for adjacent to each other). Servers should not output fields for
articles that have been removed since the overview database articles that have been removed since the overview database
was created. was created.
Note that all US-ASCII tab characters in any header data that Note that all US-ASCII tab characters in any header data that
is returned will be converted to a single US-ASCII space is returned will be converted to a single US-ASCII space
character. A contiguous sequence of US-ASCII non-printing character. A contiguous sequence of US-ASCII non-printing
characters will be compressed to a single US-ASCII space characters will be compressed to a single US-ASCII space
character in any output response. character in any output response.
10.4.9.1 Responses 9.4.9.1 Responses
224 Overview information follows 224 Overview information follows
412 No news group current selected 412 No news group current selected
420 No article(s) selected 420 No article(s) selected
502 no permission 502 no permission
10.4.10 PAT 9.4.10 PAT
PAT header range|<message-id> [pat [pat...]] PAT header range|<message-id> [pat [pat...]]
The PAT command is used to retrieve specific headers from The PAT command is used to retrieve specific headers from
specific articles, based on pattern matching on the contents specific articles, based on pattern matching on the contents
of the header. of the header.
The required header parameter is the name of a header line The required header parameter is the name of a header line
(e.g. "subject") in a news group article. See RFC-1036 for a (e.g. "subject") in a news group article. See RFC-1036 for a
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list of valid header lines. The required range argument may be list of valid header lines. The required range argument may be
any of the following: any of the following:
. an article number . an article number
. an article number followed by a dash to indicate all following . an article number followed by a dash to indicate all following
. an article number followed by a dash followed by another . an article number followed by a dash followed by another
article number. article number.
The required message-id argument indicates a specific article. The required message-id argument indicates a specific article.
The range and message-id arguments are mutually exclusive. If The range and message-id arguments are mutually exclusive. If
there are additional arguments, they are joined together there are additional arguments, they are joined together
separated by a single space to form one complete pattern. If separated by a single space to form one complete pattern. If
there are no additional arguments, a wildmat "*" is the there are no additional arguments, a wildmat "*" is the
default. Successful responses start with a 221 response default. Successful responses start with a 221 response
followed by article number, an US-ASCII space, and the header followed by article number, an US-ASCII space, and the header
from that message in which the pattern matched the contents of from that message in which the pattern matched the contents of
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the specified header line. A valid response includes an empty the specified header line. A valid response includes an empty
list (indicating that there was no matches). Once the output list (indicating that there was no matches). Once the output
is complete, a period is sent on a line by itself. If the is complete, a period is sent on a line by itself. If the
optional argument is a message-id and no such article exists, optional argument is a message-id and no such article exists,
the 430 error response shall be returned. A 502 response shall the 430 error response shall be returned. A 502 response shall
be returned if the client only has permission to transfer be returned if the client only has permission to transfer
articles. articles.
10.4.10.1 Responses 9.4.10.1 Responses
221 Header follows 221 Header follows
430 no such article 430 no such article
502 no permission 502 no permission
11. The CONCLUSION Step 10. The CONCLUSION Step
11.1 QUIT 10.1 QUIT
QUIT QUIT
The server process MUST acknowledge the QUIT command and then The server process MUST acknowledge the QUIT command and then
closes the connection to the client. This is the preferred closes the connection to the client. This is the preferred
method for a client to indicate that it has finished all its method for a client to indicate that it has finished all its
transactions with the NNTP server. transactions with the NNTP server.
If a client simply disconnects (or the connection times out or If a client simply disconnects (or the connection times out or
some other fault occurs), the server SHALL gracefully cease some other fault occurs), the server SHALL gracefully cease
its attempts to service the client. its attempts to service the client.
11.1.1 Responses 10.1.1 Responses
205 closing connection - goodbye! 205 closing connection - goodbye!
12. Other Keywords Barber [Page 27]
11. Other Keywords
There are other Keywords that may be used at any time between There are other Keywords that may be used at any time between
the beginning of a session and its termination. Using these the beginning of a session and its termination. Using these
keywords do not alter any state information, but the response keywords do not alter any state information, but the response
generated from the use of these keywords may provide useful generated from the use of these keywords may provide useful
information to clients that use them. information to clients that use them.
12.1 DATE 11.1 DATE
DATE DATE
This command exists to help clients find out the current time This command exists to help clients find out the current time
from the server's perspective. This command should not be from the server's perspective. This command should not be
used as a substitute for NTP[9], but to provide information used as a substitute for NTP[8], but to provide information
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that might be useful when using the NEWNEWS command (see that might be useful when using the NEWNEWS command (see
section 12.4). section 11.4).
This command returns a one-line response code of 111 followed This command returns a one-line response code of 111 followed
by the UTC (or GMT) date and time on the server in the form by the UTC (or GMT) date and time on the server in the form
YYYYMMDDhhmmss. YYYYMMDDhhmmss.
12.1.1 Responses 11.1.1 Responses
111 YYYYMMDDhhmmss 111 YYYYMMDDhhmmss
12.2 The HELP Command 11.2 The HELP Command
HELP HELP
This command provides a short summary of commands that are This command provides a short summary of commands that are
understood by this implementation of the server. The help text understood by this implementation of the server. The help text
will be presented as a textual response terminated by a single will be presented as a textual response terminated by a single
period on a line by itself. period on a line by itself.
This text is not guaranteed to be in any particular format and This text is not guaranteed to be in any particular format and
shall not be used by clients as a replacement for the LIST shall not be used by clients as a replacement for the LIST
EXTENSIONS command described in section 8.1. EXTENSIONS command described in section 8.1.
12.2.1 Responses 11.2.1 Responses
100 help text follows 100 help text follows
12.3 NEWGROUPS 11.3 NEWGROUPS
NEWGROUPS date time [GMT|UTC] [<distributions>] NEWGROUPS date time [GMT|UTC] [<distributions>]
A list of newsgroups created since <date and time> MUST be A list of newsgroups created since <date and time> MUST be
listed in the same format as the LIST command. listed in the same format as the LIST command.
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The date is sent as 6 or 8 digits in the format [XX]YYMMDD, The date is sent as 6 or 8 digits in the format [XX]YYMMDD,
where XX is the first two digits of the year, YY is the last where XX is the first two digits of the year, YY is the last
two digits of the year, MM is the two digits of the month two digits of the year, MM is the two digits of the month
(with leading zero, if appropriate), and DD is the day of the (with leading zero, if appropriate), and DD is the day of the
month (with leading zero, if appropriate). If the first two month (with leading zero, if appropriate). If the first two
digits of the year are not specified, the year is to be taken digits of the year are not specified, the year is to be taken
from the current century if YY is smaller than or equal to the from the current century if YY is smaller than or equal to the
current year, otherwise the year is from the previous century. current year, otherwise the year is from the previous century.
Time must also be specified. It must be as 6 digits HHMMSS Time must also be specified. It must be as 6 digits HHMMSS
with HH being hours in the 24-hour clock 00-23, MM minutes 00- with HH being hours in the 24-hour clock 00-23, MM minutes 00-
59, and SS seconds 00-60, which allows for leap seconds. The 59, and SS seconds 00-60, which allows for leap seconds. The
tokens "GMT" and "UTC" specifies that the date and time are tokens "GMT" and "UTC" specifies that the date and time are
given in UTC. If the tokens "GMT" and "UTC" are omitted then given in UTC. If the tokens "GMT" and "UTC" are omitted then
the date and time are specified in the server's local the date and time are specified in the server's local
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timezone. Note that there is no way within this specification timezone. Note that there is no way within this specification
of NNTP to establish the server's local timezone. of NNTP to establish the server's local timezone.
The optional parameter "distributions" is a list of The optional parameter "distributions" is a list of
distribution groups, enclosed in angle brackets. If distribution groups, enclosed in angle brackets. If
specified, the distribution portion of an article's header specified, the distribution portion of an article's header
will be examined for a match with the distribution categories will be examined for a match with the distribution categories
listed, and only those articles which have a distribution in listed, and only those articles which have a distribution in
the list will be listed. If more than one distribution is to the list will be listed. If more than one distribution is to
be supplied, they must be separated by commas within the angle be supplied, they must be separated by commas within the angle
brackets. brackets.
Note that an empty list (i.e., the text body returned by this Note that an empty list (i.e., the text body returned by this
command consists only of the terminating period) is a possible command consists only of the terminating period) is a possible
valid response, and indicates that there are currently no new valid response, and indicates that there are currently no new
newsgroups. newsgroups.
Clients SHOULD make all queries using GMT/UTC time when Clients SHOULD make all queries using GMT/UTC time when
possible. possible.
12.3.1 Responses 11.3.1 Responses
231 list of new newsgroups follows 231 list of new newsgroups follows
12.4 NEWNEWS 11.4 NEWNEWS
NEWNEWS newsgroups date time [GMT] [<distributions>] NEWNEWS newsgroups date time [GMT] [<distributions>]
A list of message-ids of articles posted or received to the A list of message-ids of articles posted or received to the
specified news group since "date" will be listed. The format specified news group since "date" will be listed. The format
of the listing will be one message-id per line, as though text of the listing will be one message-id per line, as though text
were being sent. A single line consisting solely of one were being sent. A single line consisting solely of one
period followed by CR-LF will terminate the list. period followed by CR-LF will terminate the list.
Date and time are in the same format as the NEWGROUPS command. Date and time are in the same format as the NEWGROUPS command.
The newsgroups parameter must be in wildmat format and may The newsgroups parameter must be in wildmat format and may
consist of multiple wildmat constructs separated by an US- consist of multiple wildmat constructs separated by an US-
ASCII comma character. ASCII comma character.
Barber [Page 29]
The optional parameter "distributions" is a list of The optional parameter "distributions" is a list of
distribution groups, enclosed in angle brackets. If distribution groups, enclosed in angle brackets. If
specified, the distribution portion of an article's header specified, the distribution portion of an article's header
will be examined for a match with the distribution categories will be examined for a match with the distribution categories
listed, and only those articles which have a distribution in listed, and only those articles which have a distribution in
the list will be listed. If more than one distribution is to the list will be listed. If more than one distribution is to
be supplied, they must be separated by commas within the angle be supplied, they must be separated by commas within the angle
brackets. brackets.
The use of the IHAVE, NEWNEWS, and NEWGROUPS commands to
distribute news is discussed in an earlier part of this
document.
Barber [Page 32]
Note that an empty list (i.e., the text body returned by this Note that an empty list (i.e., the text body returned by this
command consists only of the terminating period) is a possible command consists only of the terminating period) is a possible
valid response, and indicates that there is currently no new valid response, and indicates that there is currently no new
news. news.
Clients SHOULD make all queries in GMT/UTC time when possible. Clients SHOULD make all queries in GMT/UTC time when possible.
12.4.1 Responses 11.4.1 Responses
230 list of new articles by message-id follows 230 list of new articles by message-id follows
13. Framework for NNTP Extensions Barber [Page 30]
12. Framework for NNTP Extensions
Although NNTP is widely and robustly deployed, some parts of Although NNTP is widely and robustly deployed, some parts of
the Internet community might wish to extend the NNTP service. the Internet community might wish to extend the NNTP service.
This memo defines a means whereby an extended NNTP client may This memo defines a means whereby an extended NNTP client may
query the server to determine the service extensions that it query the server to determine the service extensions that it
supports. supports.
It must be emphasized that any extension to the NNTP service It must be emphasized that any extension to the NNTP service
should not be considered lightly. NNTP's strength comes should not be considered lightly. NNTP's strength comes
primarily from its simplicity. Experience with many protocols primarily from its simplicity. Experience with many protocols
skipping to change at line 1730 skipping to change at page 34, line ?
b) a registry of NNTP service extensions b) a registry of NNTP service extensions
The LIST EXTENSIONS command is described in section 8.1 of The LIST EXTENSIONS command is described in section 8.1 of
this memo and is the mechanism for clients to use to determine this memo and is the mechanism for clients to use to determine
what extensions are available for client use. what extensions are available for client use.
The IANA shall maintain a registry of NNTP service extensions. The IANA shall maintain a registry of NNTP service extensions.
Associated with each such extension is a corresponding NNTP Associated with each such extension is a corresponding NNTP
keyword value. Each service extension registered with the IANA keyword value. Each service extension registered with the IANA
Barber [Page 33]
MUST be defined in an RFC. Such RFCs either must be on the MUST be defined in an RFC. Such RFCs either must be on the
standards-track or must define an IESG-approved experimental standards-track or must define an IESG-approved experimental
protocol. The definition must include: protocol. The definition must include:
. the textual name of the NNTP service extension; . the textual name of the NNTP service extension;
. the label that is returned by LIST EXTENSIONS that would . the label that is returned by LIST EXTENSIONS that would
indicate to the client that the server supports this indicate to the client that the server supports this
particular extension. particular extension.
. any new NNTP keywords associated with the extension; . any new NNTP keywords associated with the extension;
. the syntax and possible values of parameters associated with . the syntax and possible values of parameters associated with
the new NNTP keywords; the new NNTP keywords;
. any new parameters the extension associates with any other . any new parameters the extension associates with any other
pre-existing NNTP verbs; pre-existing NNTP verbs;
Barber [Page 31]
. how support for the extension affects the behavior of a server . how support for the extension affects the behavior of a server
and client NNTP; and, and client NNTP; and,
. the increment by which the extension is increasing the maximum . the increment by which the extension is increasing the maximum
length of the any commands over that specified in this length of the any commands over that specified in this
document. document.
In addition, any NNTP keyword value that starts with an upper In addition, any NNTP keyword value that starts with an upper
or lower case "X" refers to a local NNTP service extension, or lower case "X" refers to a local NNTP service extension,
which is used through bilateral, rather than standardized, which is used through bilateral, rather than standardized,
agreement. Keywords beginning with "X" may not be used in a agreement. Keywords beginning with "X" may not be used in a
registered service extension. registered service extension.
skipping to change at line 1768 skipping to change at page 34, line ?
or IESG-approved experimental NNTP service extension or IESG-approved experimental NNTP service extension
registered with IANA. A conforming server must not offer non registered with IANA. A conforming server must not offer non
"X" prefixed keyword values that are not described in a "X" prefixed keyword values that are not described in a
registered extension. registered extension.
Additional verbs are bound by the same rules as NNTP keywords; Additional verbs are bound by the same rules as NNTP keywords;
specifically, verbs beginning with "X" are local extensions specifically, verbs beginning with "X" are local extensions
that may not be registered or standardized and verbs not that may not be registered or standardized and verbs not
beginning with "X" must always be registered. beginning with "X" must always be registered.
13.1 Initial IANA Registry 12.1 Initial IANA Registry
The IANA's initial registry of NNTP service extensions The IANA's initial registry of NNTP service extensions
consists of these entries: consists of these entries:
Service Extension NNTP Extension Label Added Behavior Service Extension NNTP Extension Label Added Behavior
Overview Support OVER Defined in this Overview Support OVER Defined in this
document document
Specific Article LISTGROUP Defined in this Specific Article LISTGROUP Defined in this
Numbers document Numbers document
Barber [Page 34]
Simple AUTHINFO Defined in this
Identification and document
Authentication
Generic AUTHINFO-GENERIC Defined in this
Identification and document
Authentication
Header Pattern PAT Defined in this Header Pattern PAT Defined in this
Matching document Matching document
14. Augmented BNF[10] Syntax for NNTP Commands 13. Augmented BNF[9] Syntax for NNTP Commands
This syntax defines the non-terminal "command". The non-terminal This syntax defines the non-terminal "command". The non-terminal
"parameter" is used for command parameters whose syntax is "parameter" is used for command parameters whose syntax is
specified elsewhere. The syntax is in alphabetical order. Note specified elsewhere. The syntax is in alphabetical order. Note
that ABNF strings are case insensitive. that ABNF strings are case insensitive.
article-command = "ARTICLE" [1*WSP (msg-id / article-number)] article-command = "ARTICLE" [1*WSP (msg-id / article-number)]
*WSP CRLF *WSP CRLF
Barber [Page 32]
article-number = 1*16DIGIT article-number = 1*16DIGIT
augument = parameter ; excluding sequence ".." augument = parameter ; excluding sequence ".."
authenticator = parameter ; excluding sequence ".."
authinfo-generic-command = "AUTHINFO" 1*WSP "GENERIC" 1*WSP
authenticator *(1*WSP argument) *WSP CRLF
authinfo-pass-command = "AUTHINFO" 1*WSP "PASS" 1*WSP password
*WSP CRLF
authinfo-user-command = "AUTHINFO" 1*WSP "USER" 1*WSP username
*WSP CRLF
body-command = "BODY" [1*WSP (msg-id / article-number)] *WSP body-command = "BODY" [1*WSP (msg-id / article-number)] *WSP
CRLF CRLF
command = article-command / command = article-command /
authinfo-generic-command /
authinfo-pass-command /
authinfo-user-command /
body-command / body-command /
date-command / date-command /
group-command / group-command /
head-command / head-command /
help-command / help-command /
ihave-command / ihave-command /
last-command / last-command /
list-active-times-command / list-active-times-command /
list-distrib-pats-command / list-distrib-pats-command /
list-distributions-command / list-distributions-command /
list-extensions-command / list-extensions-command /
list-newsgroups-command / list-newsgroups-command /
list-overview-fmt-command / list-overview-fmt-command /
list-subscriptions-command / list-subscriptions-command /
list-command / list-command /
listgroup-command / listgroup-command /
Barber [Page 35]
mode-reader-command / mode-reader-command /
newgroups-command / newgroups-command /
newnews-command / newnews-command /
next-command / next-command /
over-command / over-command /
pat-command / pat-command /
post-command / post-command /
quit-command / quit-command /
stat-command stat-command
CR = %x0D CR = %x0D
skipping to change at line 1868 skipping to change at page 34, line ?
LF = %x0A LF = %x0A
list-active-times-command = "LIST" 1*WSP "ACTIVE.TIMES" list-active-times-command = "LIST" 1*WSP "ACTIVE.TIMES"
[1*WSP wildmat] *WSP CRLF [1*WSP wildmat] *WSP CRLF
list-command = "LIST" [1*WSP "ACTIVE" [1*WSP wildmat]] *WSP list-command = "LIST" [1*WSP "ACTIVE" [1*WSP wildmat]] *WSP
CRLF CRLF
list-distrib-pats-command = "LIST" 1*WSP "DISTRIB.PATS" *WSP list-distrib-pats-command = "LIST" 1*WSP "DISTRIB.PATS" *WSP
CRLF CRLF
list-distributions-command = "LIST" 1*WSP "DISTRIBUTIONS" *WSP list-distributions-command = "LIST" 1*WSP "DISTRIBUTIONS" *WSP
CRLF CRLF
list-extensions-command = "LIST" 1*WSP "EXTENSIONS" *WSP CRLF list-extensions-command = "LIST" 1*WSP "EXTENSIONS" *WSP CRLF
Barber [Page 33]
list-newsgroups-command = "LIST" 1*WSP "NEWSGROUPS" [1*WSP list-newsgroups-command = "LIST" 1*WSP "NEWSGROUPS" [1*WSP
wildmat] wildmat]
*WSP CRLF *WSP CRLF
list-overview-fmt-command = "LIST" 1*WSP "OVERVIEW.FMT" *WSP list-overview-fmt-command = "LIST" 1*WSP "OVERVIEW.FMT" *WSP
CRLF CRLF
list-subscriptions-command = "LIST" 1*WSP "SUBSCRIPTIONS" *WSP list-subscriptions-command = "LIST" 1*WSP "SUBSCRIPTIONS" *WSP
CRLF CRLF
listgroup-command = "LISTGROUP" [1*WSP newsgroup] *WSP CRLF listgroup-command = "LISTGROUP" [1*WSP newsgroup] *WSP CRLF
mode-reader-command = "MODE" 1*WSP "READER" *WSP CRLF mode-reader-command = "MODE" 1*WSP "READER" *WSP CRLF
msg-id = <defined in RFC822> msg-id = <defined in RFC822>
skipping to change at line 1889 skipping to change at page 34, line ?
"GMT"/"UTC"][1*WSP "<" distribution *("," distribution) "GMT"/"UTC"][1*WSP "<" distribution *("," distribution)
">"] *WSP CRLF ">"] *WSP CRLF
newnews-command = "NEWNEWS" 1*WSP newsgroup *("," newsgroup) newnews-command = "NEWNEWS" 1*WSP newsgroup *("," newsgroup)
1*WSP date 1*WSP time [1*WSP "GMT"/"UTC"] 1*WSP date 1*WSP time [1*WSP "GMT"/"UTC"]
[1*WSP "<" distribution *("," distribution) ">"] [1*WSP "<" distribution *("," distribution) ">"]
*WSP CRLF *WSP CRLF
newsgroup = parameter newsgroup = parameter
next-command = "NEXT" *WSP CRLF next-command = "NEXT" *WSP CRLF
over-command = "OVER" [1*WSP range] *WSP CRLF over-command = "OVER" [1*WSP range] *WSP CRLF
parameter = 1*(%x21-FF) ; generic command parameter parameter = 1*(%x21-FF) ; generic command parameter
Barber [Page 36]
password = parameter
pat-command = "PAT" 1*WSP header 1*WSP (range / msg-id) pat-command = "PAT" 1*WSP header 1*WSP (range / msg-id)
*(1*WSP wildmat) *WSP CRLF *(1*WSP wildmat) *WSP CRLF
post-command = "POST" *WSP CRLF post-command = "POST" *WSP CRLF
quit-command = "QUIT" *WSP CRLF quit-command = "QUIT" *WSP CRLF
range = article-number ["-" [article-number]] range = article-number ["-" [article-number]]
SP = %x20 SP = %x20
stat-command = "STAT" [1*WSP (msg-id / article-number)] *WSP stat-command = "STAT" [1*WSP (msg-id / article-number)] *WSP
CRLF CRLF
time = 6DIGIT time = 6DIGIT
username = parameter
UTF-8-non-ascii = %xC0-FF 1*(%x80-BF) ; UTF-8 encoding of non- UTF-8-non-ascii = %xC0-FF 1*(%x80-BF) ; UTF-8 encoding of non-
ASCII character ASCII character
wildmat = 1*("*" / "?" / wildmat-exact / wildmat-set / wildmat = 1*("*" / "?" / wildmat-exact / wildmat-set /
"\" (%x21-7F / UTF-8-non-ascii)) "\" (%x21-7F / UTF-8-non-ascii))
wildmat-exact = %x21-29 / %x2B-3E / %x40-5A / %x5D-7F / UTF-8- wildmat-exact = %x21-29 / %x2B-3E / %x40-5A / %x5D-7F / UTF-8-
non-ascii non-ascii
; exclude space * ? [ \ ; exclude space * ? [ \
wildmat-non-hyphen = %x21-2C / %x2E-7F / UTF-8-non-ascii ; wildmat-non-hyphen = %x21-2C / %x2E-7F / UTF-8-non-ascii ;
exclude space - exclude space -
wildmat-set = "[" ["^"] ["]" / "-"] *(wildmat-non-hyphen ["-" wildmat-set = "[" ["^"] ["]" / "-"] *(wildmat-non-hyphen ["-"
WSP = SP / HT WSP = SP / HT
15. Security Considerations 14. Security Considerations
The use of the AUTHINFO is optional. This command as
documented has a number of security implications. In the
original form, all passwords are passed in plain text and
could be discovered by various forms of network or system
surveillance. The AUTHINFO GENERIC command has the potential
for the same problems if a mechanism is used that also passes
clear text passwords. RFC 1731 discusses these issues in
greater detail.
16. References There are no specific security mechanisms proposed in this standard,
though such mechanisms may be added via the extensions process.
15. References
1 Kantor, B and P. Lapsley, "Network News Transfer Protocol", 1 Kantor, B and P. Lapsley, "Network News Transfer Protocol",
RFC-977, U.C. San Diego and U.C. Berkeley. RFC-977, U.C. San Diego and U.C. Berkeley.
2 Yergeau, F., "UTF-8, a transformation format of Unicode and 2 Yergeau, F., "UTF-8, a transformation format of Unicode and
ISO 10646", RFC 2044, Alis Technologies. ISO 10646", RFC 2044, Alis Technologies.
3 Coded Character Set-7-bit American Standard Code for 3 Coded Character Set-7-bit American Standard Code for
Information Interchange, ANSI x3.4-1986. Information Interchange, ANSI x3.4-1986.
4 Bradner, Scott, "Key words for use in RFCs to Indicate 4 Bradner, Scott, "Key words for use in RFCs to Indicate
Requirement Levels", RFC-2119, Harvard University. Requirement Levels", RFC-2119, Harvard University.
5 Salz, Rich, Manual Page for wildmat(3) from the INN 1.4 5 Salz, Rich, Manual Page for wildmat(3) from the INN 1.4
distribution, UUNET Technologies, Revision 1.10, April, 1992. distribution, UUNET Technologies, Revision 1.10, April, 1992.
6 Horton, M.R. and R. Adams, "Standard for interchange of 6 Horton, M.R. and R. Adams, "Standard for interchange of
USENET messages", RFC-1036, AT&T Bell Laboratories and Center USENET messages", RFC-1036, AT&T Bell Laboratories and Center
for Seismic Studies, December, 1987. for Seismic Studies, December, 1987.
Barber [Page 37] 7 Robertson, Rob, "FAQ: Overview database / NOV General
7 Meyers, J, "IMAP4 Authentication Mechanisms", RFC-1731,
Carnegie Mellon, December, 1994.
8 Robertson, Rob, "FAQ: Overview database / NOV General
Information", ftp://ftp.uu.net/networking/news/nntp/inn/faq- Information", ftp://ftp.uu.net/networking/news/nntp/inn/faq-
nov.Z, January, 1995. nov.Z, January, 1995.
9 Mills, David L., "Network Time Protocol (Version 3), 8 Mills, David L., "Network Time Protocol (Version 3),
Specification, Implementation and Analysis", RFC-1305, Specification, Implementation and Analysis", RFC-1305,
University of Delaware, March 1992. University of Delaware, March 1992.
10 Crocker, D. and Overell, P., "Augmented BNF for Syntax 9 Crocker, D. and Overell, P., "Augmented BNF for Syntax
Specifications: ABNF", RFC-2234, Internet Mail Consortium and Specifications: ABNF", RFC-2234, Internet Mail Consortium and
Demon Internet, Ltd. Demon Internet, Ltd.
17. Notes 16. Notes
DEC is a registered trademark of Digital Equipment DEC is a registered trademark of Compaq Computer Corporation.
Corporation.
UNIX is a registered trademark of the X/Open Consortium. UNIX is a registered trademark of the X/Open Consortium.
VMS is a registered trademark of Digital Equipment VMS is a registered trademark of Compaq Equipment Corporation.
Corporation.
18. Acknowledgments 17. Acknowledgments
The author acknowledges the original authors of NNTP as The author acknowledges the original authors of NNTP as
documented in RFC 977: Brian Kantor and Phil Lapsey. documented in RFC 977: Brian Kantor and Phil Lapsey.
The author gratefully acknowledges the work of the NNTP The author gratefully acknowledges the work of the NNTP
committee chaired by Eliot Lear. The organization of this committee chaired by Eliot Lear. The organization of this
document was influenced by the last available draft from this document was influenced by the last available draft from this
working group. A special thanks to Eliot for generously working group. A special thanks to Eliot for generously
providing the original machine readable sources for that providing the original machine readable sources for that
document. document.
skipping to change at line 2004 skipping to change at line 1823
. Clive D.W. Feather <clive@demon.net> . Clive D.W. Feather <clive@demon.net>
. Chris Lewis <clewis@bnr.ca> . Chris Lewis <clewis@bnr.ca>
. Tom Limoncelli <tal@mars.superlink.net> . Tom Limoncelli <tal@mars.superlink.net>
. Eric Schnoebelen <eric@egsner.cirr.com> . Eric Schnoebelen <eric@egsner.cirr.com>
. Rich Salz <rsalz@osf.org> . Rich Salz <rsalz@osf.org>
This work was precipitated by the work of various newsreader This work was precipitated by the work of various newsreader
authors and newsserver authors, which includes those listed authors and newsserver authors, which includes those listed
below: below:
. Rick Adams-Original author of the NNTP extensions to the RN . Rick Adams -- Original author of the NNTP extensions to the RN
newsreader and last maintainer of Bnews newsreader and last maintainer of Bnews
. Stan Barber-Original author of the NNTP extensions to the . Stan Barber -- Original author of the NNTP extensions to the
newsreaders that are part of Bnews. newsreaders that are part of Bnews.
. Geoff Collyer -- Original author of the OVERVIEW database
Barber [Page 38]
. Geoff Collyer-Original author of the OVERVIEW database
proposal and one of the original authors of CNEWS proposal and one of the original authors of CNEWS
. Dan Curry-Original author of the xvnews newsreader . Dan Curry -- Original author of the xvnews newsreader
. Wayne Davision"Author of the first threading extensions to the . Wayne Davision -- Author of the first threading extensions to the
RN newsreader (commonly called TRN). RN newsreader (commonly called TRN).
. Geoff Huston-Original author of ANU NEWS . Geoff Huston -- Original author of ANU NEWS
. Phil Lapsey-Original author of the UNIX reference . Phil Lapsey -- Original author of the UNIX reference
implementation implementation
. Ian Lea-Former Maintainer of the TIN newsreader . Ian Lea -- Maintainer of the TIN newsreader
. Chris Lewis-First known implementor of the AUTHINFO GENERIC . Rich Salz -- Original author of INN
extension . Henry Spencer -- One of the original authors of CNEWS
. Rich Salz-Original author of INN . Kim Storm -- Original author of the NN newsreader
. Henry Spencer-One of the original authors of CNEWS
. Kim Storm-Original author of the NN newsreader
19. Author's Address 18. Author's Address
Stan Barber Stan Barber
P.O. Box 300481 P.O. Box 300481
Houston, Texas, 77230 Houston, Texas, 77230
Email: <sob@academ.com> Email: <sob@academ.com>
This document expires September 30, 1998. This document expires January 7, 1999.
Barber [Page 39] Barber [Page 36]
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