There are two forms to the ARTICLE command (and the related BODY, HEAD, and STAT commands), each using a different method of specifying which article is to be retrieved. When the ARTICLE command is followed by a message-id in angle brackets ("<" and ">"), the first form of the command is used; when a numeric parameter or no parameter is supplied, the second form is invoked.
The text of the article is returned as a textual response, as described earlier in this document.
The HEAD and BODY commands are identical to the ARTICLE command except that they respectively return only the header lines or text body of the article.
The STAT command is similar to the ARTICLE command except that no text is returned. When selecting by message number within a group, the STAT command serves to set the current article pointer without sending text. The returned acknowledgement response will contain the message-id, which may be of some value. Using the STAT command to select by message-id is valid but of questionable value, since a selection by message-id does NOT alter the "current article pointer".
ARTICLE <message-id>
Display the header, a blank line, then the body (text) of the specified article. Message-id is the message id of an article as shown in that article's header. It is anticipated that the client will obtain the message-id from a list provided by the NEWNEWS command, from references contained within another article, or from the message-id provided in the response to some other commands.
Please note that the internally-maintained "current article pointer" is NOT ALTERED by this command. This is both to facilitate the presentation of articles that may be referenced within an article being read, and because of the semantic difficulties of determining the proper sequence and membership of an article which may have been posted to more than one newsgroup.
ARTICLE [nnn]
Displays the header, a blank line, then the body (text) of the current or specified article. The optional parameter nnn is the numeric id of an article in the current newsgroup and must be chosen from the range of articles provided when the newsgroup was selected. If it is omitted, the current article is assumed.
The internally-maintained "current article pointer" is set by this command if a valid article number is specified.
[the following applies to both forms of the article command.] A response indicating the current article number, a message-id string, and that text is to follow will be returned.
The message-id string returned is an identification string contained within angle brackets ("<" and ">"), which is derived from the header of the article itself. The Message-ID header line (required by RFC850) from the article must be used to supply this information. If the message-id header line is missing from the article, a single digit "0" (zero) should be supplied within the angle brackets.
Since the message-id field is unique with each article, it may be used by a news reading program to skip duplicate displays of articles that have been posted more than once, or to more than one newsgroup.
220 n <a> article retrieved - head and body follow
(n = article number, <a> = message-id)
221 n <a> article retrieved - head follows
222 n <a> article retrieved - body follows
223 n <a> article retrieved - request text separately
412 no newsgroup has been selected
420 no current article has been selected
423 no such article number in this group
430 no such article found