In <yladi0oe6k(_dot_)fsf(_at_)windlord(_dot_)stanford(_dot_)edu> Russ Allbery
<rra(_at_)stanford(_dot_)edu> writes:
Keith Moore <moore(_at_)cs(_dot_)utk(_dot_)edu> writes:
it would be interesting to know what the problems are, especially since
IDNA or something close to it seems likely to be used in email
addresses.
I'm not at all sure that I agree with Charles's blithe assertions about
the opinion of USEFOR, but the one objection that was raised to IDNA is
that it has some potentially somewhat unfortunate side effects when it
comes to Usenet feed patterns. Right now, it's common to attempt to
exclude certain types of binaries with patterns like @*mp3* and @*dvd*; so
long as all newsgroup names are ASCII words, this works fairly well, but
once you start using an encoding like IDNA, the chances of odd false
positives and negatives is quite high.
That is actually a very good point. There is an expectation, built into
NNTP, that users will be able to filter newsgroup-names using "wildmats"
(which are a restricted form of regular expression). The draft of the new
NNTP standard (draft-ietf-nntpext-base-15.txt) goes to considerable
trouble to define wildmats in such a way that they will work with UTF-8.
But for sure they would not work with anything encoded using punycode.
Indeed, that may turn out to be a problem with anyone who wants to filter
out domains of the form "*.æøå.com" from his incoming emails.
--
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131 Fax: +44 161 436 6133 Web: http://www.cs.man.ac.uk/~chl
Email: chl(_at_)clw(_dot_)cs(_dot_)man(_dot_)ac(_dot_)uk Snail: 5
Clerewood Ave, CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5