INTERNET-DRAFT S. Barber
Expires: November 25, 1995 Academ Consulting Services
June 1995
Common NNTP Extensions
draft-barber-nntp-imp-01.txt
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Abstract
In this document, a number of popular extensions to the NNTP
protocol defined in RFC977 are documented and discussed. While
this document is not intended to serve as a standard of any kind,
it will hopefully serve as a reference document for future
implementors of the NNTP protocol. In the role, this document
would hopefully create the possibility for some level of
interoperability among implementations that make use of extensions.
Introduction
RFC977[1] defines the NNTP protocol and was released almost
a decade ago. Since then, NNTP has become one of the most
popular protocols in use on the Internet. Many implementations
of the protocol have been created on many different platforms
and operating systems. With the growth in use of the
protocol, work began on a revision to NNTP in 1991, but
that work did not result in a new protocol specification.
However, many ideas from that working group did find their
way into many implementations of NNTP. Additionally, many
other extensions are also in use. This document will capture
and define all known extensions to NNTP as of this writing.
It is the hope of the authors that using this document in
tandem with RFC977 will limit the addition of new extensions
that essentially do the same thing and provide for the
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creation of a new forum to discuss an official revision of
the NNTP specification.
This document does not specify an Internet Standard of any
kind. It only attempts to document current practices.
While this document may clarify some ambiguity in RFC977,
RFC977 should be regarded as authoritative in all cases.
There are some implementations that are not strictly RFC977
compliant and where necessary, these deviations from the
standard will be noted.
Extensions fall into three categories: transport, newsreader
and other. Transport extensions are additions to the NNTP
specification that were made specifically to move news
articles from one server to another server. Newsreader
extensions are additions to the NNTP specification that
were made to assist NNTP clients in selecting and retrieving
news articles from servers. Other extensions to the NNTP
specification are those which did not specifically fall
into either of the other two categories. Examples of other
extensions include authentication and time-of-day extensions.
For each command, the format of section 3 of RFC977 will be used.
1. Transport Extensions
Following are the descriptions of each transport extension
commands and the responses which will be returned by those
commands.
Each command is shown in upper case for clarity, although
case is ignored in the interpretation of commands by the
NNTP server. Any parameters are shown in lower case. A
parameter shown in [square brackets] is optional. For
example, [GMT] indicates that the triglyph GMT may present
or omitted. A parameter that may be repeated is followed
by an ellipsis.
1.1.1 The XPATH command
XPATH <message-id>
The XPATH command is used to determine the filenames in
which an article is filed.
The required parameter message-id is the message id of an
article as shown in that article's header. According to
RFC 1036[2], all message ids for all articles within the
netnews environment are unique, but articles may be
crossposted to multiple groups. The response to an XPATH
command will include a listing of all filenames in which
an article is stored separated by spaces or a response
indicating that no article with the specified message-id
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exists.
1.1.2. Responses
223 path1[ path2 ...]
430 no such article on server
1.2.1 The XREPLIC command
XREPLIC ggg:nnn[,ggg:nnn...]
The XREPLIC command makes is possible to exactly duplicate
the news spool structure of one server in another server.
This command works similarly to the IHAVE command as
specified in RFC977. The same response codes are used. The
command line arguments consist of entries separated by a
single comma. Each entry consists of a news group name, a
colon, and an article number. If the server responses with
a 335 response, the article should be filed in the news
group(s) and article number(s) specified in the XREPLIC
command line. If the server cannot do successfully install
the article once it has accepted it, a 436 or 437 response
code can be used to indicate the failure.
This command should only be used when the receiving server
is being fed by only one other server. It is likely that
when used with servers that have multiple feeds that this
command will frequently fail.
1.2.2. Responses
235 article transferred ok
335 send article to be transferred. End with <CR-LF>.<CR-LF>
435 article not wanted - do not send it
436 transfer failed - try again later
437 article rejected - do not try again
2. Newsreader Extensions
Following are the descriptions of each newsreader extension
commands and the responses which will be returned by those
commands.
Each command is shown in upper case for clarity, although
case is ignored in the interpretation of commands by the
NNTP server. Any parameters are shown in lower case. A
parameter shown in [square brackets] is optional. For
example, [GMT] indicates that the triglyph GMT may present
or omitted. A parameter that may be repeated is followed
by an ellipsis. Mutually exclusive parameters are separated
by a vertical bar (|) character. For example, ggg|<message-id>
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indicates that a group name or a <message-id> may be
specified, but not both.
Also, certain commands make use of a pattern for selection
of multiple news groups. The pattern in all cases is based
on the wildmat[3] format introduced by Rich Salz in 1986.
Arguments expected to be in wildmat format will be
represented by the string wildmat. This format is discussed
in detail in section 3.3 of this document.
2.1.1 Extensions to the LIST command
The original LIST command took no arguments in RFC977 and
returned the contents of the active file in a specific
format. Since the original newsreaders made use of other
information available in the news transport software in
addition to the active file, extensions to the LIST command
were created to make that information available to NNTP
newsreaders.
2.1.2 LIST ACTIVE
LIST ACTIVE [wildmat]
LIST ACTIVE is exactly the same as the LIST command specified in
RFC977. The responses and the format should exactly match the LIST
command without arguments. If the optional matching parameter is
specified, the list is limited to only the groups that match the
pattern. Specifying a single group is usually very efficient for
the server, and multiple groups may be specified by using wildmat
patterns (similar to file globbing), not regular expressions.
If nothing is matched an empty list is returned, not an error.
2.1.3 LIST ACTIVE.TIMES
LIST ACTIVE.TIMES
The active.times file is maintained by some news transports
systems to contain information about the when and who
created a particular news group. The format of this file
generally include three fields. The first field is the name
of the news group. The second is the time when this group
was created on this news server measured in seconds since
January 1, 1970. The third is the email address of the
entity that created the news group. When executed, the
information is displayed following the 215 response. When
display is completed, the server will send a period on a
line by itself. If the information is not available, the
server will return the 503 error response.
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2.1.3.1 Responses
215 information follows
503 program error, function not performed
2.1.4 LIST DISTRIBUTIONS
LIST DISTRIBUTIONS
The distributions file is maintained by some news transport
systems to contain information about valid values for the
Distributions: line in a news article header and about what
the values mean. Each line contains two fields, the value
and a short explanation on the meaning of the value. When
executed, the information is displayed following the 215
response. When display is completed, the server will send
a period on a line by itself. If the information is not
available, the server will return the 503 error response.
2.1.4.1 Responses
215 information follows
503 program error, function not performed
2.1.5 LIST DISTRIB.PATS
LIST DISTRIB.PATS
The distrib.pats file is maintained by some news transport
systems to contain default values for the Distribution:
line in a news article header when posting to particular
news groups. This information could be used to provide a
default value for the Distribution: line in the header when
posting an article. The information returned involves three
fields separated by colons. The first column is a weight.
The second is a group name or a pattern that can be used
to match a group name in the wildmat format. The third is
the value of the Distribution: line that should be used
when the group name matches and the weight value is the
highest. All this processing is done by the news posting
client and not by the server itself. The server just provides
this information to the client for it to use or ignore as
it chooses. When executed, the information is displayed
following the 215 response. When display is completed,
the server will send a period on a line by itself. If the
information is not available, the server will return the
503 error response.
2.1.5.1 Responses
215 information follows
503 program error, function not performed
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2.1.6 LIST NEWSGROUPS
LIST NEWSGROUPS [wildmat]
The newsgroups file is maintained by some news transport
systems to contain the name of each news group which is
active on the server and a short description about the
purpose of the news groups. Each line in the file contains
two fields, the news group name and a short explanation of
the purpose of the news group. When executed, the information
is displayed following the 215 response. When display is
completed, the server will send a period on a line by
itself. If the information is not available, the server
will return the 503 response. If the optional matching
parameter is specified, the list is limited to only the groups
that match the pattern (no matching is done on the group
descriptions). Specifying a single group is usually very
efficient for the server, and multiple groups may be specified
by using wildmat patterns (similar to file globbing),
not regular expressions. If nothing is matched an empty list
is returned, not an error.
When the optional parameter is specified, this command is
equivalent to the XGTITLE command, though the response code
are different.
2.1.6.1 Responses
215 information follows
503 program error, function not performed
2.1.7 LIST OVERVIEW.FMT
LIST OVERVIEW.FMT
The overview.fmt file is maintained by some news transport
systems to contain the order in which header information
is stored in the overview databases for each news group.
When executed, news article header fields are displayed
one line at a time in the order in which they are stored
in the overview database[4] following the 215 response.
When display is completed, the server will send a period
on a line by itself. If the information is not available,
the server will return the 503 response.
Please note that if the header has the word "full" (without
quotes) after the colon, the header's name is prepended
to its field in the output returned by the server.
2.1.7.1 Responses
215 information follows
503 program error, function not performed
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2.1.8 LIST SUBSCRIPTIONS
LIST SUBSCRIPTIONS
This command is used to get a default subscription list for
new users of this server. The order of groups is significant.
When this list is available, it is preceded by the 215
response and followed by a period on a line by itself. When
this list is not available, the server returns a 503 response
code.
2.1.8.1 Responses
215 information follows
503 program error, function not performed
2.2 LISTGROUP
LISTGROUP [ggg]
The LISTGROUP command is used to get a listing of all the
article numbers in a particular news group.
The optional parameter ggg is the name of the news group
to be selected (e.g. "news.software.b"). A list of valid
news groups may be obtained from the LIST command. If no
group is specified, the current group is used as the default
argument.
The successful selection response will be a list of the
article numbers in the group followed by a period on a line
by itself.
When a valid group is selected by means of this command,
the internally maintained "current article pointer" is set
to the first article in the group. If an invalid group is
specified, the previously selected group and article remain
selected. If an empty news group is selected, the "current
article pointer" is in an indeterminate state and should
not be used.
Note that the name of the news group is not case-dependent.
It must otherwise match a news group obtained from the LIST
command or an error will result.
2.2.1 Responses
211 list of article numbers follow
412 Not currently in newsgroup
502 no permission
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2.3 MODE QUERY
MODE QUERY
MODE QUERY is the same as MODE READER. See section 2.4.
2.4 MODE READER
MODE READER is used by the client to indicate to the server
that it is a news reading client. Some implementations make
use of this information to reconfigure themselves for better
performance in responding to news reader commands.
2.4.1 Responses
200 Hello, you can post
201 Hello, you can't post
2.5 XGTITLE
XGTITLE [wildmat]
The XGTITLE command is used to retrieve news group descriptions
for specific news groups.
This extension first appeared in ANU-NEWS, an NNTP
implementation for DEC's VMS. The optional parameter is a
pattern in wildmat format. When executed, a 282 response
is given followed by lines that have two fields, the news
group name (which matches the pattern in the argument) and
a short explanation of the purpose of the news group. When
no argument is specified, the default argument is the
current group name. When display is completed, the server
sends a period on a line by itself.
Please note that this command and the LIST NEWSGROUP command
provide the same functionality with different response codes.
2.5.1 Responses
282 list of groups and descriptions follows
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2.6 XHDR
XHDR header [range|<message-id>]
The XHDR command is used to retrieve specific headers from
specific articles.
The required parameter is the name of a header line (e.g.
"subject") in a news group article. See RFC-1036 for a list
of valid header lines. The optional range argument may be
any of the following:
an article number
an article number followed by a dash to indicate
all following
an article number followed by a dash followed by
another article number
The optional message-id argument indicates a specific
article. The range and message-id arguments are mutually
exclusive. If no argument is specified, then information
from the current article is displayed. Successful responses
start with a 221 response followed by a the matched headers
from all matched messages. Once the output is complete, a
period is sent on a line by itself. If the optional argument
is a message-id and no such article exists, the 430 error
response is returned. If a range is specified, a news group
must have been selected earlier, else a 412 error response
is returned. If no articles are in the range specified, a
420 error response is returned by the server. A 502 response
will be returned if the client only has permission to
transfer articles.
The XHDR command has been available in the UNIX reference
implementation from its first release. However, until now,
it has only been documented in the source for the server.
2.6.1 Responses
221 Header follows
412 No news group current selected
420 No current article selected
430 no such article
502 no permission
2.7 XINDEX
XINDEX ggg
The XINDEX command is used to retrieve an index file in
the format of originally created for use by the TIN[5] news
reader.
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 may be obtained from the LIST command.
The successful selection response will return index file
in the format used by the TIN news reader followed by a
period on a line by itself.
When a valid group is selected by means of this command,
the internally maintained "current article pointer" is set
to the first article in the group. If an invalid group is
specified, the previously selected group and article remain
selected. If an empty news group is selected, the "current
article pointer" is in an indeterminate state and should
not be used.
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Note that the name of the news group is not case-dependent.
It must otherwise match a news group obtained from the LIST
command or an error will result.
The format of the tin-style index file is discussed in the
documentation for the TIN newsreader. Since more recent
versions of TIN support the news overview (NOV) format, it
is recommended that this extension become historic and no
longer be used in current servers or future implementations.
2.7.1 Responses
218 tin-style index follows
418 no tin-style index is available for this news group
2.8 XOVER
XOVER [range]
The XOVER command returns information from the overview
database for the article(s) specified.
The optional range argument may be any of the following:
an article number
an article number followed by a dash to indicate
all following
an article number followed by a dash followed by
another article number
If no argument is specified, then information from the
current article is displayed. Successful responses start
with a 224 response followed by the overview information
for all matched messages. Once the output is complete, a
period is sent on a line by itself. If no argument is
specified, the information for the current article is
returned. A news group must have been selected earlier,
else a 412 error response is returned. If no articles are
in the range specified, a 420 error response is returned
by the server. A 502 response will be returned if the
client only has permission to transfer articles.
The output will be formatted with the article number,
followed by each of the headers in the overview database
for that article separated by a tab character.
2.8.1 Responses
224 Overview information follows
412 No news group current selected
420 No article(s) selected
502 no permission
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2.9 XPAT
XPAT header range|<message-id> pat [pat...]
The XPAT command is used to retrieve specific headers from
specific articles.
The required parameter is the name of a header line (e.g.
"subject") in a news group article. See RFC-1036 for a list
of valid header lines. The required range argument may be
any of the following:
an article number
an article number followed by a dash to indicate
all following
an article number followed by a dash followed by
another article number
The required message-id argument indicates a specific
article. The range and message-id arguments are mutually
exclusive. At least one pattern in wildmat must be specified
as well. If there are additional arguments the are joined
together separated by a single space to form the complete
pattern. Successful responses start with a 221 response
followed by a the headers from all matched messages. Once
the output is complete, a period is sent on a line by
itself. If the optional argument is a message-id and no
such article exists, the 430 error response is returned.
A 502 response will be returned if the client only has
permission to transfer articles.
2.9.1 Responses
221 Header follows
430 no such article
502 no permission
2.10 XROVER
XROVER [range]
The XROVER command returns reference information from the
overview database for the article(s) specified.
The optional range argument may be any of the following:
an article number
an article number followed by a dash to indicate
all following
an article number followed by a dash followed by
another article number
Successful responses start with a 224 response followed by
the overview information for all matched messages. Once
the output is complete, a period is sent on a line by
itself. If no argument is specified, the information for
the current article is returned. A news group must have
been selected earlier, else a 412 error response is returned.
If no articles are in the range specified, a 420 error
response is returned by the server. A 502 response will be
returned if the client only has permission to transfer
articles.
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The output will be formatted with the article number,
followed by reference overview information separated by a
tab character.
2.10.1 Responses
224 Overview information follows
412 No news group current selected
420 No article(s) selected
502 no permission
2.11 XTHREAD
XTHREAD [DBINIT|THREAD]
The XTHREAD command is used to retrieve threading information
in format of originally created for use by the TRN[6] news
reader.
The command XTHREAD DBINIT may be issued prior to entering
any groups to see if a thread database exists. If it does,
the database's byte order and version number are returned
as binary data.
If no parameter is given, XTHREAD THREAD is assumed.
To use XTHREAD THREAD, a news group must have been selected
earlier, else a 412 error response is returned.
A 502 response will be returned if the client only has
permission to transfer articles. A 503 response is returned
if the threading files are not available.
The format of the trn-style thread format is discussed in
the documentation for the TRN newsreader. Since more recent
versions of TRN support the news overview (NOV) format, it
is recommended that this extension become historic and no
longer be used in current servers or future implementations.
2.11.1 Responses
288 Binary data to follow
412 No newsgroup current selected
502 No permission
503 program error, function not performed
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3. Other Extensions
3.1 AUTHINFO
AUTHINFO is used to inform a server about the identity of
a user of the server. In all cases, clients must provide
this information when requested by the server. Servers are
not required to accept authentication information that is
volunteered by the client. Clients must accommodate servers that
reject any authentication information volunteered by the client.
There are three forms of AUTHINFO in use. The original version,
an NNTP v2 revision called AUTHINFO SIMPLE and a more recent
version which is called AUTHINFO GENERIC.
3.1.1 Original AUTHINFO
AUTHINFO USER username
AUTHINFO PASS password
The original AUTHINFO is used to identify a specific entity
to the server using a simple username/password combination.
When authorization is required, the server will send a 480
response requesting authorization from the client. The
client must enter AUTHINFO USER followed by the username.
Once sent, the server will cache the username and send a
381 response requesting the password associated with that
username. The client must enter AUTHINFO PASS followed by
the password for the username. The server will then check
the authentication database to see if the username/password
combination is valid. If the combination is valid, the
server will return a 281 response. The client should then
retry the original command to which the server responded
with the 480 response. The command should then be processed
by the server normally. If the combination is not valid,
the server will return a 502 response.
Clients must provide authentication when requested by the server.
It is possible that some implementations will accept authentication
information at the beginning of a session, but this was not the
original intent of the specification. If a client attempts to
reauthenticate, the server may return 482 response indicating
that the new authentication data is rejected by the server.
The 482 code will also be returned when the AUTHINFO commands
are not entered in the correct sequence (like two AUTHINFO
USERs in a row, or AUTHINFO PASS preceding AUTHINFO USER).
All information is passed in cleartext.
When authentication succeeds, the server will create an email
address for the client from the user name supplied in the
AUTHINFO USER command and the hostname generated by a reverse
lookup on the IP address of the client. If the reverse lookup
fails, the IP address, represented in dotted-quad format, will
be used. Once authenticated, the server shall generate a Sender:
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line using the email address provided by authentication if it
does not match the client-supplied From: line. Additionally,
the server should log the event, including the email address
This will provide a means by which subsequent statistics generation
can associate newsgroup references with unique entities - not
necessarily by name.
3.1.1.1 Responses
281 Authentication accepted
381 More authentication information required
480 Authentication required
482 Authentication rejected
502 No permission
3.1.2 AUTHINFO SIMPLE
AUTHINFO SIMPLE
user password
This version of AUTHINFO was part of the proposed NNTP V2
specification and is implemented in some servers and clients.
It is a refinement of the original AUTHINFO and provides
the same basic functionality, but the sequence of commands
is much simpler.
When authorization is required, the server sends a 450 response
requesting authorization from the client. The client must enter
AUTHINFO SIMPLE. If the server will accept this form of
authentication, the server responds with a 350 response. The
client must then send the username followed by one or more
space characters followed by the password. If accepted, the
server returns a 250 response and the client should then
retry the original command to which the server responded
with the 451 response. The command should then be processed
by the server normally. If the combination is not valid,
the server will return a 452 response.
Note that the response codes used here were part of the
NNTP V2 specification and are violations of RFC 977. It
is recommended that this command not be implemented, but
use either or both of the other forms of AUTHINFO if such
functionality if required.
3.1.2.1 Responses
250 Authorization accepted
350 Continue with authorization sequence
450 Authorization required for this command
452 Authorization rejected
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3.1.3 AUTHINFO GENERIC
AUTHINFO GENERIC authenticator arguments...
AUTHINFO GENERIC is used to identify a specific entity to the
server using arbitrary authentication or identification
protocols. The desired protocol is indicated by the
authenticator parameter, and any number of parameters can
be passed to the authenticator.
When authorization is required, the server will send a 380
response requesting authorization from the client. The
client should enter AUTHINFO GENERIC followed by the
authenticator name, and the arguments if any. The authenticator
and arguments must not contain the sequence "..".
The server will attempt to engage the server end authenticator,
similarly, the client should engage the client end authenticator.
The server end authenticator will then initiate authentication
using the NNTP sockets (if appropriate for that authentication
protocol), using the protocol specified by the authenticator name.
These authentication protocols are not included in this document,
but are similar in structure to those referenced in RFC 1731[7]
for the IMAP-4 protocol.
If the server returns 501, this means that the authenticator
invocation was syntactically incorrect, or that AUTHINFO
GENERIC is not supported. The client should retry using the
AUTHINFO USER command.
If the requested authenticator capability is not found or
there is some other unspecified server program error, the
server returns the 503 response code.
The authenticators converse using their protocol until complete.
If the authentication succeeds, the server authenticator will
terminate with a 281, and the client can continue by reissuing
the command that prompted the 380. If the authentication fails,
the server will respond with a 502.
The client must provide authentication when requested by the
server. The server may request authentication at any
time. Servers may request authentication more than once
during a single session.
When the server authenticator completes, it provides to the
server (by a mechanism herein undefined) the email address
of the user, and potentially what the user is allowed to
access. Once authenticated, the server shall generate a Sender:
line using the email address provided by the authenticator
if it does not match the user-supplied From: line. Additionally,
the server should log the event, including the user's
authenticated email address (if available). This will provide
a means by which subsequent statistics generation can
associate newsgroup references with unique entities - not
necessarily by name.
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3.1.3.1 Responses
281 Authentication succeeded
380 Authentication required
501 Command not supported or Command syntax error
502 No permission
503 Program error, function not performed
nnn authenticator-specific protocol.
3.2 DATE
DATE
The NNTP v2 draft specification added this command to help
clients find out the current time from the server's perspective.
At the time this command was discussed (1991-1992), the
Network Time Protocol [8] (NTP) was not yet in wide use and there
was also some concern that small systems may not be able to make
effective use of NTP.
This command returns a one-line response code of 111 followed
by the GMT date and time on the server in the form
YYYYMMDDhhmmss.
3.2.1 Responses
111 YYYYMMDDhhmmss
3.3 The WILDMAT format
The WILDMAT format was first developed by Rich Salz to provide
a uniform mechanism for matching patterns in the same manner
that the UNIX shell matches filenames. 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 sequence of zero or
more characters. The second is a question mark (?) to match any
single character. The third specifies a specific set of
characters. The set is specified as a list of characters, or as
a range of characters where the beginning and end of the range
are separated by a minus (or dash) character, or as any
combination of lists and ranges. The dash can also be included
in the range as a character it if is the beginning or end of
the range. This set is enclosed in square brackets. The close
square bracket (]) may be used in a range if it is the first
character in the set. The fourth operation is the same as the
logical not of the third operation and is specified the same
way as the third with the addition of a caret character (^) at
the beginning of the test string just inside the open square
bracket. The final operation uses the backslash character to
invalidate the special meaning of the a open square bracket ([),
the asterisk, or the question mark.
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3.3.1 Examples
a. [^]-] -- matches any character other than a close square bracket
or a minus sign/dash.
b. *bdc -- matches any string that ends with the string "bdc"
including the string "bdc" (without quotes).
c. [0-9a-zA-Z] -- matches any alphanumeric string
d. a??d -- matches any four character string which begins
with a and ends with d.
3.4 Additional Headers
Many NNTP implementations add headers to Usenet articles when then
are POSTed via NNTP. These headers are discussed in this section.
None of these headers conflict with those specified in RFC 1036
and should be passed unchanged by Usenet transports conforming
to RFC 1036.
3.4.1 NNTP-Posting-Host
This line is added to the header of a posted article by the
server. The contents of the header is either the IP address
or the fully qualified domain name of the client host posting
the article. The fully qualified domain name should be
determined by doing a reverse lookup in the DNS on the IP
address of the client. If the client article contains this line,
it is removed by the server before acceptance of the article
by the Usenet transport system
This header provides some idea of the actual host posting
the article as opposed to information in the Sender or From
lines that may be present in the article. This is not a
fool-proof methodology since reverse lookups in the DNS
are vulnerable to certain types of spoofing, but such
discussions are outside the scope of this document.
3.4.2 X-Newsreader and others
There are other lines that are added by clients as well.
Most of these indicate the type of newsreader software
that is posting the article.
4.0 Future Work
With the continued use of NNTP on the Internet, there
remains an interest in creating an optimized transport
protocol for server-to-server transfers and an optimized
client protocol for client-to-server interactions. There
is also considerable interest is building better mechanisms
to provide audit information on which news groups are being
read by which users.
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How this will be done remains an open issue.
5.0 Security
No security issues are discussed in this document.
6.0 References
[1] Kantor, B and P. Lapsley, "Network News Transfer Protocol",
RFC-977, U.C. San Diego and U.C. Berkeley, February, 1986.
[2] Horton, M.R. and R. Adams, "Standard for interchange of USENET
messages", RFC-1036, AT&T Bell Laboratories and Center for
Seismic Studies, December, 1987.
[3] Salz, Rich, Manual Page for wildmat(3) from the INN 1.4
distribution, UUNET Technologies, Revision 1.10, April, 1992.
[4] Anderson, Robert, "FAQ: Overview database / NOV General
Information", USENET Message
<nov-faq-1-796816975@agate.Berkeley.EDU>, April, 1995.
[5] Lea, Ian, "FAQ about the TIN newsreader",
http://www.scn.de/~iain/tin/faq.html, April, 1995.
[6] Kappesser, Peter, "[news.software.readers] trn newsreader FAQ",
2 parts, USENET Messages <trn-faq-1-798889623@kong.syr.edu>
and <trn-faq-2-797679065@kong.syr.edu>, April, 1995.
[7] Meyers, J, "IMAP4 Authentication Mechanisms", RFC-1731,
Carnegie Mellon, December, 1994.
[8] Mills, David L., "Network Time Protocol (Version 3), Specification,
Implementation and Analysis", RFC-1305, University of Delaware,
March 1992.
7.0 Notes
DEC is a registered trademark of Digital Equipment Corporation.
UNIX is a registered trademark of the X/Open Consortium.
VMS is a registered trademark of Digital Equipment Corporation.
8.0 Acknowledgments
The author gratefully acknowledges the comments and additional
information provided by the following individuals:
Wayne Davison <davison@armory.com>
Chris Lewis <clewis@bnr.ca>
Eric Schnoebelen <eric@egsner.cirr.com>
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9.0 Author's Address
Stan Barber
P.O. Box 300481
Houston, Texas, 77230
Email: <sob@academ.com>
This document expires on November 25, 1995.
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