RFC Errata
RFC 3977, "Network News Transfer Protocol (NNTP)", October 2006
Note: This RFC has been updated by RFC 6048
Source of RFC: nntpext (app)
Errata ID: 2003
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: Julien Élie
Date Reported: 2010-01-14
Held for Document Update by: Peter Saint-Andre
Throughout the document, when it says:
(a) Section 6.1.3.2, last paragraph about LAST: If the current article number is already the first article of the newsgroup, a 422 response MUST be returned. If the current article number is invalid, a 420 response MUST be returned. If the currently selected newsgroup is invalid, a 412 response MUST be returned. In all three cases, the currently selected newsgroup and current article number MUST NOT be altered. (b) Section 6.1.4.2, last paragraph about NEXT: If the current article number is already the last article of the newsgroup, a 421 response MUST be returned. In all other aspects (apart, of course, from the lack of 422 response), this command is identical to the LAST command (Section 6.1.3).
It should say:
(a) Section 6.1.3.2, last paragraph about LAST: If the currently selected newsgroup is invalid, a 412 response MUST be returned. If the currently selected newsgroup is valid but the current article number is invalid, a 420 response MUST be returned. If the current article number is valid and there is no previous article in the currently selected newsgroup, a 422 response MUST be returned. In all three cases, the currently selected newsgroup and current article number MUST NOT be altered. (b) Section 6.1.4.2, last paragraph about NEXT: If the current article number is valid and there is no next article in the currently selected newsgroup, a 421 response MUST be returned. In all other aspects (apart, of course, from the lack of 422 response), this command is identical to the LAST command (Section 6.1.3).
Notes:
RFC 3977 is unclear about the 421 and 422 response codes: the first article of a newsgroup is defined as its reported low water mark, and the last article as its reported high water mark (see Section 6.1.1.2). However, there MAY be no previous article in the group, although the current article number is not the reported low water mark (see the second paragraph of Section 6.1.3.2). Therefore, a 422 response code MUST also be returned in that case. A similar case for the next article and the 421 response code exists.
The notion of "previous" and "next" article is respectively defined in the first paragraph of Sections 6.1.3.2 and 6.1.4.2.
This erratum also reverses the order of 412, 420, and 421/422 so that it is clearer that an invalid newsgroup or article number takes precedence in determining the return code.