draft-ietf-nntpext-base-06.txt   draft-ietf-nntpext-base-07.txt 
INTERNET DRAFT S. Barber INTERNET DRAFT S. Barber
Expires: January 7, 1999 Academ Consulting Services Expires: June 7, 1999 Academ Consulting Services
August 1998 December 1998
Network News Transport Protocol Network News Transport Protocol
draft-ietf-nntpext-base-06.txt draft-ietf-nntpext-base-07.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
skipping to change at page 34, line ? skipping to change at line 136
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 on the same line. Keywords MUST consist of printable
printable US-ASCII characters. Unless otherwise noted US-ASCII characters. Unless otherwise noted elsewhere in this
elsewhere in this document, Arguments SHOULD consist of document, arguments SHOULD consist of printable US-ASCII
printable US-ASCII characters. Keywords and arguments MUST be characters. Keywords and arguments MUST be each separated by
each separated by one or more US-ASCII SPACE or US-ASCII TAB one or more US-ASCII SPACE or US-ASCII TAB characters.
characters. Keywords MUST be at least three US-ASCII Keywords MUST be at least three US-ASCII characters and MUST
characters and MUST NOT exceed 12 US-ASCII characters. NOT exceed 12 US-ASCII characters. Command lines MUST NOT
Command lines MUST NOT exceed 512 octets, which includes the exceed 512 octets, which includes the terminating US-ASCII
terminating US-ASCII CRLF pair. Arguments must not exceed 497 CRLF pair. Arguments MUST NOT exceed 497 octets.
octets.
Each response MUST start with a three-digit status indicator Each response MUST start with a three-digit response code that
that is sufficient to distinguish all responses. Responses to is sufficient to distinguish all responses. Unless
certain commands MAY be multi-line. In these cases, which are specifically specified as one of the valid responses for a
clearly indicated below, after sending the first line of the command (such as those described later in this document), each
response and an US-ASCII CRLF, any additional lines are sent, response is contained in a single line. However, certain
each terminated by an US-ASCII CRLF pair. When all lines of commands MAY permit multi-line responses. All multi-line
the response have been sent, a final line MUST be sent, responses MUST adhear to the following format: After sending
consisting of a termination octet (US-ASCII decimal code 046, the first line of the response and an US-ASCII CRLF, any
".") and an US-ASCII CRLF pair. If any line of the multi-line additional lines are sent, each terminated by an US-ASCII CRLF
response begins with the termination octet, the line MUST be pair. When all lines of the response have been sent, a final
"byte-stuffed" by pre-pending the termination octet to that line MUST be sent, consisting of a termination octet (US-ASCII
line of the response. Hence, a multi-line response is decimal code 046, ".") and an US-ASCII CRLF pair. If any line
terminated with the five octets "CRLF.CRLF" (in US-ASCII). of the multi-line response begins with the termination octet,
When examining a multi-line response, the client MUST check to the line MUST be "byte-stuffed" by pre-pending the termination
see if the line begins with the termination octet. If so and octet to that line of the response. Hence, a multi-line
if octets other than US-ASCII CRLF follow, the first octet of response is terminated with the five octets "CRLF.CRLF" (in
the line (the termination octet) MUST be stripped away. If so US-ASCII). When examining a multi-line response, the client
MUST check to see if the line begins with the termination
Barber [Page 3] Barber [Page 3]
and if US-ASCII CRLF immediately follows the termination octet. If so and if octets other than US-ASCII CRLF follow,
character, then the response from the NNTP server is ended and the first octet of the line (the termination octet) MUST be
the line containing ".CRLF" (in US-ASCII) MUST NOT considered stripped away. If so and if US-ASCII CRLF immediately follows
part of the multi-line response. the termination character, then the response from the NNTP
server is ended and the line containing ".CRLF" (in US-ASCII)
MUST NOT considered part of the multi-line response. The
keywords that support multi-line responses have the format of
those responses described in the responses section.
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
sending any response to the client. sending any response to the client.
4.1 Responses Codes 4.1 Response Codes
Each response MUST begin with a three-digit response code. Each response MUST begin with a three-digit status indicator.
These are status reports from the server and indicate the These are status reports from the server and indicate the
response to the last command received from the client. response to the last command received from the client.
The first digit of the response broadly indicates the success, The first digit of the response broadly indicates the success,
failure, or progress of the previous command. failure, or progress of the previous command.
1xx - Informative message 1xx - Informative message
2xx - Command ok 2xx - Command ok
3xx - Command ok so far, send the rest of it. 3xx - Command ok so far, send the rest of it.
4xx - Command was correct, but couldn't be performed for some 4xx - Command was correct, but couldn't be performed for some
skipping to change at page 34, line ? skipping to change at line 209
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
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 can be returned in response to a
command are detailed in the description of the keyword that is given command are detailed in the description of the keyword
the first part of the command. In addition, below is listed a that is the first part of the command. In addition, below is
general set of response codes that MAY be received at any listed a general set of response codes that MAY be received at
time. any time.
Certain status responses contain parameters such as numbers Certain response codes contain parameters such as numbers and
and names. In those cases, the number and type of such names in addition to the status indicator. In those cases, the
parameters MUST be fixed for each response code to simplify number and type of such parameters MUST be fixed for each
interpretation of the response. In all other cases, the client
MUST only use the response code itself to determine the nature
of the response.
Barber [Page 4] Barber [Page 4]
Parameters MUST be separated from the numeric response code response code to simplify interpretation of the response. In
all other cases, the client MUST only use the status indicator
itself to determine the nature of the response.
Parameters MUST be separated from the numeric status indicator
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
text following a response number may vary in different text following a response number may vary in different
implementations of the server. The 3-digit numeric code should implementations of the server. The 3-digit numeric status
be used to determine what response was sent. indicator should be used to determine what response was sent.
Response codes not specified in this standard MAY be used for Response codes not specified in this standard MAY be used for
any installation-specific additional commands also not any installation-specific additional commands also not
specified. These SHOULD be chosen to fit the pattern of x8x specified. These SHOULD be chosen to fit the pattern of x8x
specified above. (Note that debugging is provided for specified above. (Note that debugging is provided for
explicitly in the x9x response codes.) explicitly in the x9x response codes.)
The use of unspecified response codes for a standard command The use of unspecified response codes for a standard command
is prohibited. is prohibited.
The response pattern x9x is provided for debugging. Since The status indicator pattern x9x is provided for debugging.
much debugging output may be classed as "informative Since much debugging output may be classed as "informative
messages", it MUST be the case that responses 190 through 199 messages", it MUST be the case that responses 190 through 199
WILL be used for various debugging outputs. There is no WILL be used for various debugging outputs. There is no
requirement in this specification for debugging output. requirement in this specification for debugging output.
However, if such is provided over the connected stream, it However, if such is provided over the connected stream, it
MUST use these response codes. If appropriate to a specific MUST use these response codes. If appropriate to a specific
implementation, other x9x codes MAY be used for debugging. implementation, other x9x codes MAY be used for debugging.
(For example, response code 290 could be used to acknowledge a (For example, response code 290 could be used to acknowledge a
remote debugging request.) remote debugging request.)
A server MUST respond to an unrecognized, unimplemented, or A server MUST respond to an unrecognized, unimplemented, or
syntactically invalid command with a negative status indicator syntactically invalid command with a negative response
(response codes of the form 5XX). A server MUST respond to a code(status indicators of the form 5XX). A server MUST
command issued when the session is in an incorrect state by respond to a command issued when the session is in an
responding with a negative status indicator. This may be from incorrect state by responding with a negative status
either the 4XX or 5XX group as appropriate. indicator. This may be from 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] described here is based on the version
on the format used in the UNIX "find" command to articulate first developed by Rich Salz which was derived from the format
file names. It was developed to provide a uniform mechanism used in the UNIX "find" command to articulate file names. It
for matching patterns in the same manner that the UNIX shell was developed to provide a uniform mechanism for matching
matches filenames. Patterns are implicitly anchored at the
beginning and end of each string when testing for a match.
There are five pattern-matching operations other than a strict
one-to-one match between the pattern and the source to be
checked for a match. The first is an asterisk (*) to match any
Barber [Page 5] Barber [Page 5]
sequence of zero or more UTF-8 characters. The second is a patterns in the same manner that the UNIX shell matches
question mark (?) to match any single UTF-8 character. The filenames. Patterns are implicitly anchored at the beginning
third specifies a specific set of characters. The set is and end of each string when testing for a match. There are
specified as a list of characters, or as a range of characters six pattern-matching operations other than a strict one-to-one
where the beginning and end of the range are separated by a match between the pattern and the source to be checked for a
minus (or dash) character, or as any combination of lists and match. The first is an asterisk (*) to match any sequence of
ranges. The dash can also be included in the set as a zero or more UTF-8 characters. The second is a question mark
character it if is the beginning or end of the set. This set (?) to match any single UTF-8 character. The third specifies a
is enclosed in square brackets. The close square bracket (]) specific set of characters. The set is specified as a list of
may be used in a set if it is the first character in the set. characters, or as a range of characters where the beginning
The fourth operation is the same as the logical not of the and end of the range are separated by a minus (or dash)
third operation and is specified the same way as the third character, or as any combination of lists and ranges. The dash
with the addition of a caret character (^) at the beginning of can also be included in the set as a character it if is the
the test string just inside the open square bracket. The final beginning or end of the set. This set is enclosed in square
operation uses the backslash character to invalidate the brackets. The close square bracket (]) may be used in a set if
special meaning of the open square bracket ([), the asterisk, it is the first character in the set. The fourth operation is
backslash or the question mark. Two backslashes in sequence the same as the logical not of the third operation and is
will result in the evaluation of the backslash as a character specified the same way as the third with the addition of a
with no special meaning. caret character (^) at the beginning of the test string just
inside the open square bracket. The fifth operation uses the
exclamation mark (!) preceding any valid expression built
using any of the operators discussed prior to this sentence.
The final operation uses the backslash character to invalidate
the special meaning of the open square bracket ([), the
asterisk, backslash, exclamation mark or the question mark.
The meaning of the backslash operator cannot be negated by the
exclamation point. Two backslashes in sequence will result in
the evaluation of the backslash as a character with no special
meaning.
5.1 Examples 5.1 Examples
a) [^]-] -- matches any single character other than a a) [^]-] -- matches any single character other than a
close square bracket or a minus sign/dash. close square bracket or a minus sign/dash.
b) *bdc -- matches any string that ends with the string b) *bdc -- matches any string that ends with the string
"bdc" including the string "bdc" (without quotes). "bdc" including the string "bdc" (without quotes).
c) [0-9a-zA-Z] -- matches any single printable c) [0-9a-zA-Z] -- matches any single printable
alphanumeric ASCII character. alphanumeric ASCII character.
d) a??d -- matches any four character string which d) a??d -- matches any four character string which
skipping to change at page 34, line ? skipping to change at line 327
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 be present or omitted. A parameter that the triglyph GMT may be present or omitted. A parameter
that may be repeated is followed by an ellipsis. Mutually that may be repeated is followed by an ellipsis. Mutually
Barber [Page 6]
exclusive parameters are separated by a vertical bar (|) exclusive parameters are separated by a vertical bar (|)
character. For example, ggg|<message-id> indicates that a character. For example, ggg|<message-id> indicates that a
group name or a <message-id> may be specified, but not both. group name or a <message-id> may be specified, but not both.
Some parameters may be case or language specific. See RFC Some parameters may be case or language specific. See RFC
1036[6] for these details. 1036[6] for these details.
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. Arguments expected to be in
Arguments expected to be in wildmat format will be represented wildmat format will be represented by the string wildmat. This
format is discussed in detail in section 5 of this memo.
Barber [Page 6]
by the string wildmat. This format is discussed in detail in
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. not authorized to post articles using the POST keyword.
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 to interact with the
the server. The server should immediately close the connection 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
MODE READER MODE READER
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
400 Service temporarily unavailable 400 Service temporarily unavailable
Barber [Page 7]
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
Barber [Page 7]
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,
501 and 502. 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. server administration). of other state information. However, a client NNTP MUST NOT
However, a client NNTP MUST NOT cache (for use in another cache (for use in another session) any information returned if
session) any information returned if the LIST EXTENSIONS the LIST EXTENSIONS command succeeds. That is, a client NNTP
command succeeds. That is, a client NNTP MUST issue the LIST is only able to get the current and correct information
EXTENSIONS command at least once during each session to get concerning available extensions during a session by issuing a
the current and correct information concerning available LIST EXTENSIONS command during that session and processing
extensions during that session. that response.
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-
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 Barber [Page 8]
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
actually add a new command or keyword. Any parameters
Barber [Page 8] included are to be specified with the definition of the
actually add a new command. Any parameters included are to be 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 and how each parameter is
seperated from other parameters.
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
independent manner. Where this is done, implementations are independent manner. Where this is done, implementations are
recommended to use upper case letters when transmitting the recommended to use US-ASCII upper case letters when
extension response. transmitting the extension response.
The LIST EXTENISONS command itself is not included in the list The LIST EXTENSIONS command itself is not included in the list
of features supported, support for the LIST EXTENSIONS command of features supported, support for the LIST EXTENSIONS command
is indicated by return of a reply other than a 500 or 502 is indicated by return of a reply other than a 500 or 502
reply. reply.
The end of the list is defined by the usual period on a line The end of the list is defined by the usual period on a line
by itself. by itself.
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] PAT [S] PAT
[S] LISTGROUP [S] LISTGROUP
[S] . [S] .
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
Barber [Page 9]
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 server 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.
Barber [Page 9]
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. No
list (not even an empty one) will be returned.
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
skipping to change at page 34, line ? skipping to change at line 522
might change the state of the server, or issue the QUIT might change the state of the server, or issue the QUIT
command (see section 10.1) if a particular extension is command (see section 10.1) if a particular extension is
required for the client to properly operate. required for the client to properly 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. Note that this is response code should must return code 400. Note that this is response code should
not be generated due to an inactivity timeout as described in not be generated due to an inactivity timeout as described in
section 4. section 4.
In the case of an error response, the client NNTP should issue In the case of any error response outlined in this section,
the QUIT command (see section 10.1). the client NNTP should issue 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
Barber [Page 10]
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.
Barber [Page 10] The client NNTP should configure itself for the basic NNTP
functionality defined in this document, or issue commands that
might change the state of the server, or issue the QUIT
command (see section 10.1) if a particular extension is
required for the client to properly operate.
9. The NEWS EXCHANGE Step 9. 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
server. . article posting to the server
9.1 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
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
skipping to change at page 34, line ? skipping to change at line 585
order of arrival timestamp; that is, articles arriving later order of arrival timestamp; that is, articles arriving later
MUST have higher numbers than those that arrive earlier. The MUST have higher numbers than those that arrive earlier. The
server SHOULD allocate the next sequential unused number to server SHOULD allocate the next sequential unused number to
each new article. each new article.
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
Barber [Page 11]
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.
9.1.1 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.
9.1.1.1 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
Barber [Page 11]
may be obtained by using the LIST keyword. See section 9.4 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.
skipping to change at page 34, line ? skipping to change at line 638
that the high water mark can be less than the low water mark. that the high water mark can be less than the low water mark.
. All three numbers will be zero. . All three numbers will be zero.
. The high water mark is greater than or equal to the low water . The high water mark is greater than or equal to the low water
mark; the estimated article count might be zero or non-zero; mark; the estimated article count might be zero or non-zero;
if non-zero, the same requirements apply as for a non-empty if non-zero, the same requirements apply as for a non-empty
group. group.
The set of articles in a group may change after the GROUP The set of articles in a group may change after the GROUP
command is carried out. That is: command is carried out. That is:
. articles may be removed from the group; . articles may be removed from the group
Barber [Page 12]
. articles may be reinstated in the group with the same article . articles may be reinstated in the group with the same article
number, but those articles MUST have numbers no less than the number, but those articles MUST have numbers no less than the
reported low water mark (note that this is a reinstatement of reported low water mark (note that this is a reinstatement of
the previous article, not a new article reusing the number); the previous article, not a new article reusing the number)
. new articles may be added with article numbers greater than . new articles may be added with article numbers greater than
the reported high water mark (if an article that was the one the reported high water mark (if an article that was the one
with the highest number has been removed, the next new article with the highest number has been removed, the next new article
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
Barber [Page 12]
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
skipping to change at page 34, line ? skipping to change at line 691
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
9.1.1.2 LAST 9.1.1.2 LAST
LAST LAST
Barber [Page 13]
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
current article number is not the reported low water mark. current article number is not the reported low water mark.
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.
Barber [Page 13]
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.
9.1.1.2.1 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
skipping to change at page 34, line ? skipping to change at line 742
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.
9.1.1.3.1 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)
Barber [Page 14]
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
9.2 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 9.1. section 9.1.
Barber [Page 14]
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.
9.2.1 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
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 The internally-maintained "current article pointer" MUST NOT
pointer" MUST NOT be altered when the message-id argument is be altered when the message-id argument is used. This is both
used. This is both to facilitate the presentation of articles to facilitate the presentation of articles that may be
that may be referenced within an article being read, and referenced within an article being read, and because of the
because of the semantic difficulties of determining the proper semantic difficulties of determining the proper sequence and
sequence and membership of an article which may have been membership of an article which may have been posted to more
posted to more than one news group. than one news group.
The internally-maintained "current article pointer" MUST be The internally-maintained "current article pointer" MUST be
set when a valid article number is specified as the argument. set when a valid article number is specified as the argument.
This includes the case when an article number is implied by This includes the case when an article number is implied by
the use of no argument. the use of no argument.
A previously valid article number MAY not remain valid if the A previously valid article number MAY become invalid if the
article has been removed. A previously invalid article number article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such MAY become valid if the article has been reinstated, but such
Barber [Page 15]
an article number MUST be no less than the reported low water an article number MUST be no less than the reported low water
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), 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 is an identification string contained
contained within angle brackets ("<" and ">"), which is within angle brackets ("<" and ">"), which is derived from the
derived from the header of the article itself. The Message-ID header of the article itself. The Message-ID header line
header line (required by RFC 1036) from the article must be (required by RFC 1036) from the article must be used to supply
used to supply this information. If the message-id header line this information. If the message-id header line is missing
is missing from the article, a single digit "0" (zero) should from the article, a single digit "0" (zero) should be supplied
be supplied within the angle brackets. 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
Barber [Page 15]
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.
9.2.1.1 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
502 Service unavailable
9.2.2 HEAD 9.2.2 HEAD
HEAD [<message-id>|nnn] HEAD [<message-id>|nnn]
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 The internally-maintained "current article pointer" MUST NOT
pointer" MUST NOT be altered when the message-id argument is be altered when the message-id argument is used. This is both
used. This is both to facilitate the presentation of articles to facilitate the presentation of articles that may be
that may be referenced within an article being read, and referenced within an article being read, and because of the
because of the semantic difficulties of determining the proper semantic difficulties of determining the proper sequence and
sequence and membership of an article which may have been membership of an article which may have been posted to more
posted to more than one news group. than one news group.
The internally-maintained "current article pointer" MUST be The internally-maintained "current article pointer" MUST be
set when a valid article number is specified as the argument. set when a valid article number is specified as the argument.
This includes the case when an article number is implied by This includes the case when an article number is implied by
the use of no argument. the use of no argument.
A previously valid article number MAY not remain valid if the Barber [Page 16]
A previously valid article number MAY become invalid if the
article has been removed. A previously invalid article number article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water an article number MUST be no less than the reported low water
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), 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
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.
Barber [Page 16]
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.
9.2.2.1 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
502 Service unavailable
9.2.3 BODY 9.2.3 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.
Please note that the internally-maintained "current article The internally-maintained "current article pointer" MUST NOT
pointer" MUST NOT be altered when the message-id argument is be altered when the message-id argument is used. This is both
used. This is both to facilitate the presentation of articles to facilitate the presentation of articles that may be
that may be referenced within an article being read, and referenced within an article being read, and because of the
because of the semantic difficulties of determining the proper semantic difficulties of determining the proper sequence and
sequence and membership of an article which may have been membership of an article which may have been posted to more
posted to more than one news group. than one news group.
Barber [Page 17]
The internally-maintained "current article pointer" MUST be The internally-maintained "current article pointer" MUST be
set when a valid article number is specified as the argument. set when a valid article number is specified as the argument.
This includes the case when an article number is implied by This includes the case when an article number is implied by
the use of no argument. the use of no argument.
A previously valid article number MAY not remain valid if the A previously valid article number MAY become invalid if the
article has been removed. A previously invalid article number article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water an article number MUST be no less than the reported low water
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), 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
Barber [Page 17]
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.
9.2.3.1 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
430 no such article found 430 no such article found
502 Service unavailable
9.2.4 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.
Please note that the internally-maintained "current article The internally-maintained "current article pointer" MUST NOT
pointer" MUST NOT be altered when the message-id argument is be altered when the message-id argument is used. This is both
used. This is both to facilitate the presentation of articles to facilitate the presentation of articles that may be
that may be referenced within an article being read, and referenced within an article being read, and because of the
because of the semantic difficulties of determining the proper semantic difficulties of determining the proper sequence and
sequence and membership of an article which may have been
posted to more than one news group. Barber [Page 18]
membership of an article which may have been posted to more
than one news group.
The internally-maintained "current article pointer" MUST be The internally-maintained "current article pointer" MUST be
set when a valid article number is specified as the argument. set when a valid article number is specified as the argument.
This includes the case when an article number is implied by This includes the case when an article number is implied by
the use of no argument. the use of no argument.
A previously valid article number MAY not remain valid if the A previously valid article number MAY become invalid if the
article has been removed. A previously invalid article number article has been removed. A previously invalid article number
MAY become valid if the article has been reinstated, but such MAY become valid if the article has been reinstated, but such
an article number MUST be no less than the reported low water an article number MUST be no less than the reported low water
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
Barber [Page 18]
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.
9.2.4.1 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
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
502 Service unavailable
9.3 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.
9.3.1 POST 9.3.1 POST
POST POST
Barber [Page 19]
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
text forming the header and body of the message to be posted text forming the header and body of the message to be posted
MUST be sent by the client using the conventions for text MUST be sent by the client using the conventions for text
received from the news server: A single period (".") on a line received from the news server: A single period (".") on a line
skipping to change at page 34, line ? skipping to change at line 1033
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.
Barber [Page 19]
9.3.1.1 Responses 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
9.3.2 IHAVE 9.3.2 IHAVE
IHAVE <message-id> IHAVE <message-id>
skipping to change at page 34, line ? skipping to change at line 1060
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
manner specified for text transmission from the server. The manner specified for text transmission from the server. The
server MUST return a response code indicating success or server MUST return a response code indicating success or
failure of the transferal of the article. failure of the transferal of the article.
This function differs from the POST command in that it is This function differs from the POST command in that it is
intended for use in transferring already-posted articles intended for use in transferring already-posted articles
between hosts. Normally it will not be used when the client is between hosts. It SHOULD NOT be used when the client is a
a personal news reading program. In particular, this function
Barber [Page 20]
personal news reading program. In particular, this function
will invoke the server's news posting program with the will invoke the server's news posting program with the
appropriate settings (flags, options, etc.) to indicate that appropriate settings (flags, options, etc.) to indicate that
the forthcoming article is being forwarded from another host. the forthcoming article is being forwarded from another host.
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.
9.3.2.1 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
Barber [Page 20]
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.
9.4 The LIST Keyword 9.4 The LIST Keyword
9.4.1 LIST 9.4.1 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
skipping to change at page 34, line ? skipping to change at line 1113
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
number of the last known article currently in that news group, number of the last known article currently in that news group,
<first> is the number of the first article currently in the <first> is the number of the first article currently in the
news group, and <status> indicates the current status of the news group, and <status> indicates the current status of the
group on this server. Typically, the <status> will be consist group on this server. Typically, the <status> will be consist
of the US-ASCII character `y' where posting is permitted, `n' of the US-ASCII character `y' where posting is permitted, `n'
where posting is not permitted and `m' where postings will be where posting is not permitted and `m' where postings will be
forwarded to the news group moderator by the news server. forwarded to the news group moderator by the news server.
Barber [Page 21]
Other status strings may exist. The definition of these other Other status strings may exist. The definition of these other
values are covered in other specifications. values are covered in other specifications.
The <first> and <last> fields will always be numeric. They The <first> and <last> fields will always be numeric. They
may have leading zeros. If the <last> field evaluates to less may have leading zeros. If the <last> field evaluates to less
than the <first> field, there are no articles currently on than the <first> field, there are no articles currently on
file in the news group. file in the news group.
Note that posting may still be prohibited to a client although Note that posting may still be prohibited to a client although
the LIST command indicates that posting is permitted to a the LIST command indicates that posting is permitted to a
skipping to change at page 34, line ? skipping to change at line 1138
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.
Barber [Page 21]
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.
9.4.1.1 Responses 9.4.1.1 Responses
215 list of news groups follows 215 list of news groups follows
9.4.2 LIST ACTIVE.TIMES 9.4.2 LIST ACTIVE.TIMES
LIST ACTIVE.TIMES [wildmat] LIST ACTIVE.TIMES [wildmat]
The active.times file is maintained by some news transport The active.times file is maintained by some news transport
systems to contain information about when and who created a systems to contain information about when and who created 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 the start of
The third is the email address of the entity that created the January 1, 1970. The third is the email address of the entity
news group. When executed, the information is displayed that created the news group. When executed, the information is
following the 215 response. When display is completed, the displayed following the 215 response. When display is
server will send a period on a line by itself. If the completed, the server will send a period on a line by itself.
information is not available, the server will return the 503 If the information is not available, the server will return
error response. the 503 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.
Barber [Page 22]
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
9.4.2.1 Responses 9.4.2.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
9.4.3 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
Barber [Page 22]
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.
9.4.3.1 Responses 9.4.3.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
9.4.4 LIST DISTRIB.PATS 9.4.4 LIST DISTRIB.PATS
skipping to change at page 34, line ? skipping to change at line 1220
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.
Barber [Page 23]
9.4.4.1 Responses 9.4.4.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
9.4.5 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
Barber [Page 23]
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.
9.4.5.1 Responses 9.4.5.1 Responses
skipping to change at page 34, line ? skipping to change at line 1267
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[7] 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 If the header has the word "full" (without quotes) after the
quotes) after the colon, the header's name is prepended to its colon, the header's name is prepended to its field in the
field in the output returned by the server. output returned by the server.
Barber [Page 24]
This is command is part of the optional OVER extension which
includes the OVER command defined in section 9.4.9. If the
OVER extension is not implemented, then this command MUST NOT
be implemented.
9.4.6.1 Responses 9.4.6.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
9.4.7 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.
Barber [Page 24]
9.4.7.1 Responses 9.4.7.1 Responses
215 information follows 215 information follows
503 program error, function not performed 503 program error, function not performed
9.4.8 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
skipping to change at page 34, line ? skipping to change at line 1321
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
Barber [Page 25]
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.
The LISTGROUP command is an optional extension. It MAY be
implemented. If it is not implemented, then the LISTGROUP
label MUST NOT be included in the response to the LIST
EXTENSIONS command.
9.4.8.1 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
9.4.9 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
Barber [Page 25]
. 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.
skipping to change at page 34, line ? skipping to change at line 1374
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.
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
Barber [Page 26]
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.
The OVER command is part of the OVER extension, which includes
the LIST OVERVIEW.FMT command. The OVER extension is optional.
If it is not implemented, the response to the LIST EXTENSIONS
command must not include the OVER label.
9.4.9.1 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
9.4.10 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
Barber [Page 26]
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
the specified header line. A valid response includes an empty the specified header line. A valid response includes an empty
Barber [Page 27]
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.
The PAT command is optional. If it is not implemented, the
response to the LIST EXTENSIONS command must not include the
PAT label.
9.4.10.1 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
10. The CONCLUSION Step 10. The CONCLUSION Step
10.1 QUIT 10.1 QUIT
skipping to change at page 34, line ? skipping to change at line 1466
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.
10.1.1 Responses 10.1.1 Responses
205 closing connection - goodbye! 205 closing connection - goodbye!
Barber [Page 27]
11. Other Keywords 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.
11.1 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
Barber [Page 28]
used as a substitute for NTP[8], but to provide information used as a substitute for NTP[8], but to provide information
that might be useful when using the NEWNEWS command (see that might be useful when using the NEWNEWS command (see
section 11.4). 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.
11.1.1 Responses 11.1.1 Responses
skipping to change at page 34, line ? skipping to change at line 1504
11.2 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.
11.2.1 Responses 11.2.1 Responses
100 help text follows 100 help text follows
11.3 NEWGROUPS 11.3 NEWGROUPS
NEWGROUPS date time [GMT|UTC] [<distributions>] NEWGROUPS date time [GMT|UTC]
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.
Barber [Page 28]
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
Barber [Page 29]
the date and time are specified in the server's local the date and time are specified in the server's local
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
distribution groups, enclosed in angle brackets. If
specified, the distribution portion of an article's header
will be examined for a match with the distribution categories
listed, and only those articles which have a distribution in
the list will be listed. If more than one distribution is to
be supplied, they must be separated by commas within the angle
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.
11.3.1 Responses 11.3.1 Responses
231 list of new newsgroups follows 231 list of new newsgroups follows
11.4 NEWNEWS 11.4 NEWNEWS
NEWNEWS newsgroups date time [GMT] [<distributions>] NEWNEWS newsgroups date time [GMT]
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
distribution groups, enclosed in angle brackets. If
specified, the distribution portion of an article's header
will be examined for a match with the distribution categories
listed, and only those articles which have a distribution in
the list will be listed. If more than one distribution is to
be supplied, they must be separated by commas within the angle
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 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.
11.4.1 Responses 11.4.1 Responses
230 list of new articles by message-id follows 230 list of new articles by message-id follows
Barber [Page 30]
12. Framework for NNTP Extensions 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.
Barber [Page 30]
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
has shown that: has shown that:
Protocols with few options tend towards ubiquity, whilst Protocols with few options tend towards ubiquity, whilst
protocols with many options tend towards obscurity. protocols with many options tend towards obscurity.
This means that each and every extension, regardless of its This means that each and every extension, regardless of its
benefits, must be carefully scrutinized with respect to its benefits, must be carefully scrutinized with respect to its
skipping to change at page 34, line ? skipping to change at line 1618
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
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
. 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" MUST NOT be used in a
registered service extension. registered service extension.
Barber [Page 31]
Any keyword values presented in the NNTP response that do not Any keyword values presented in the NNTP response that do not
begin with "X" must correspond to a standard, standards-track, begin with "X" must correspond to a standard, standards-track,
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 MUST NOT be registered or standardized and verbs not
beginning with "X" must always be registered. beginning with "X" must always be registered.
12.1 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
skipping to change at page 34, line ? skipping to change at line 1677
13. Augmented BNF[9] 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 ".."
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 /
body-command / body-command /
date-command / date-command /
group-command / group-command /
head-command / head-command /
help-command / help-command /
ihave-command / ihave-command /
Barber [Page 32]
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 /
skipping to change at page 34, line ? skipping to change at line 1714
over-command / over-command /
pat-command / pat-command /
post-command / post-command /
quit-command / quit-command /
stat-command stat-command
CR = %x0D CR = %x0D
CRLF = CR LF CRLF = CR LF
date-command = "DATE" *WSP CRLF date-command = "DATE" *WSP CRLF
date = 6*8DIGIT date = 6*8DIGIT
DIGIT = %x30-39 DIGIT = %x30-39
distribution = parameter
group-command = "GROUP" 1*WSP newsgroup *WSP CRLF group-command = "GROUP" 1*WSP newsgroup *WSP CRLF
head-command = "HEAD" [1*WSP (msg-id / article-number)] *WSP head-command = "HEAD" [1*WSP (msg-id / article-number)] *WSP
CRLF CRLF
header = parameter header = parameter
help-command = "HELP" *WSP CRLF help-command = "HELP" *WSP CRLF
HT = %x09 HT = %x09
ihave-command = "IHAVE" 1*WSP msg-id *WSP CRLF ihave-command = "IHAVE" 1*WSP msg-id *WSP CRLF
last-command = "LAST" *WSP CRLF last-command = "LAST" *WSP CRLF
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>
newgroups-command = "NEWGROUPS" 1*WSP date 1*WSP time [1*WSP newgroups-command = "NEWGROUPS" 1*WSP date 1*WSP time [1*WSP
"GMT"/"UTC"][1*WSP "<" distribution *("," distribution) "GMT"/"UTC"] *WSP CRLF
">"] *WSP CRLF
Barber [Page 33]
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) ">"]
*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
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
UTF-8-non-ascii = %xC0-FF 1*(%x80-BF) ; UTF-8 encoding of non- UTF-8-non-ascii = UTF8-2 / UTF8-3 / UTF8-4 / UTF8-5 / UTF8-6
ASCII character UTF8-1 = %x80-BF
wildmat = 1*("*" / "?" / wildmat-exact / wildmat-set / UTF8-2 = %xC0-DF UTF8-1
"\" (%x21-7F / UTF-8-non-ascii)) UTF8-3 = %xE0-EF 2UTF8-1
wildmat-exact = %x21-29 / %x2B-3E / %x40-5A / %x5D-7F / UTF-8- UTF8-4 = %xF0-F7 3UTF8-1
non-ascii UTF8-5 = %xF8-FB 4UTF8-1
; exclude space * ? [ \ UTF8-6 = %xFC-FD 5UTF8-1
wildmat = 1*("!" / "*" / "?" / wildmat-exact / wildmat-set /
"\" (%x22-7F / UTF-8-non-ascii))
wildmat-exact = %x22-29 / %x2B-3E / %x40-5A / %x5D-7F / UTF-8-
non-ascii ; 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
14. Security Considerations 14. Security Considerations
There is a serious need for good text to put in this section.
Here is an attempt:
There are no specific security mechanisms proposed in this standard, The nature of network news over its history has been the
though such mechanisms may be added via the extensions process. sharing of information, seemingly without restriction. While
this was reasonable when NNTP was first specified, the lack of
a mechanism for restricting access to network news may no
longer be appropriate. This specification has some provisions
in it which make it possible to add authentication and
identification mechanisms, but none are included in this
specification. It is expected that those mechanisms will be
defined as specific extensions using the extension mechanism
specified in this document.
15. References 15. Notes
1 Kantor, B and P. Lapsley, "Network News Transfer Protocol",
UNIX is a registered trademark of the X/Open Consortium.
Barber [Page 34]
16. References
[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 ISO 10646",
ISO 10646", RFC 2044, Alis Technologies. RFC 2278, 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.
7 Robertson, Rob, "FAQ: Overview database / NOV General [7] 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.
8 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.
9 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.
16. Notes Barber [Page 35]
DEC is a registered trademark of Compaq Computer Corporation.
UNIX is a registered trademark of the X/Open Consortium.
VMS is a registered trademark of Compaq Equipment Corporation.
17. 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
skipping to change at line 1830 skipping to change at line 1871
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 . 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 -- Maintainer of the TIN newsreader . Ian Lea -- Maintainer of the TIN newsreader
. Rich Salz -- Original author of INN . Rich Salz -- Original author of INN
. Henry Spencer -- One of the original authors of CNEWS . Henry Spencer -- One of the original authors of CNEWS
. Kim Storm -- Original author of the NN newsreader . Kim Storm -- Original author of the NN newsreader
18. 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 January 7, 1999. This document expires June 7, 1999.
Barber [Page 36] Barber [Page 36]
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/