Case-sensitivity in newsgroup names and message-IDs

[Julien ÉLIE <julien@xxxxxxxxxxxxxxx>]

Hi,

Following a discussion between Mateusz Viste, Russ Allbery, Urs Janßen
and me on news.software.nntp (see <bsjlf6-frq.ln1@xxxxxxxxxxxxxxxxxxxxx>),
it appears there is a problem with case-sensitivity of a newsgroup name
and a message-ID.

The following paragraph from RFC 3977 applies:

3.1.  Commands and Responses

  Keywords are case insensitive; the case of keywords for commands MUST
  be ignored by the server.  Command and response arguments are case or
  language specific only when stated, either in this document or in
  other relevant specifications.

In practice, news servers implement:

GROUP news.software.nntp
211 3219 149 6892 news.software.nntp

GROUP news.software.NNTP
411 No such group news.software.NNTP

that is to say that news.software.nntp and news.software.NNTP are *not*
the same newsgroup.  The same behaviour occurs if I use:

Newsgroups: news.software.NNTP

in the headers of an article.  The post is rejected.


Message-IDs are also parsed case-sensitively but that fact is not
said in RFC 3977.


Besides, I read in RFC 5536 (USEFOR):

  Some software will try to match the <id-right> of a <msg-id> in a
  case-insensitive fashion; some will match it in a case-sensitive
  fashion.  Implementations MUST NOT generate a Message-ID where the
  only difference from another Message-ID is the case of characters in
  the <id-right> part.

  NOTE:  All-digit <component>s conflict with one widely used storage
  scheme for articles.  Mixed-case groups cause confusion between
  systems with case-sensitive matching and systems with case-
  insensitive matching of <newsgroup-name>s.


It does not say pretty well what is the expected behaviour!  For
message-IDs, only <id-right>s are dealt with.  What for <id-left>?!?
(In RFC 5322?  but I did not find it clearly.)
And nothing explicitly states that newsgroups are case-sensitive...


In Son of 1036, it was said:

| 2.5. Case-Sensitivity
|
|          Text  in  newsgroup  names, header parameters, etc. is case-
|          sensitive unless stated otherwise.
|
|               NOTE: This is at  variance  with  MAIL,  which  is
|               case-insensitive  unless  stated otherwise, but is
|               consistent  with  news  historical  practice   and
|               existing news software.  See the comments on back-
|               ward compatibility in section 1.

|          As with From addresses, a message ID's local part  is case-
|          sensitive  and  its domain is case-insensitive.  The "<" and
|          ">" are parts of the message ID, not  peculiarities  of the
|          Message-ID header.

|               NOTE: Possibly newsgroup names  should  have  been
|               case-insensitive, but all existing software treats
|               them as case-sensitive.   (RFC  977  [rrr]  claims
|               that they are case-insensitive in NNTP, but exist-
|               ing implementations are believed to ignore  this.)
|               The simplest solution is just to ban use of upper-
|               case letters, since no widespread  newsgroup  name
|               uses  them  anyway; this avoids any possibility of
|               confusion.


Such comments are no longer present in USEFOR.
Shouldn't something be done on that subject?

--
Julien ÉLIE

« Les idées fausses ne sont pas toujours mauvaises. » (Marcel Aymé)