> I see no reason why a protocol cannot introduce a > higher-level rule which prohibits the use of PUA characters.
And indeed IDN (Internationalised domain names) does so.
Basically, IDNs aren't private, or, if you will, the established
agreement for IDNs is not to interpret PUA characters at all,
except for prohibiting them, as are surrogate code points
(when not properly paired in UTF-16), non-characters, and
code points that weren't assigned in Unicode 3.2 (the latter
will change with a new version of IDN).
/kent k
http://www.ietf.org/rfc/rfc3454.txt
http://www.ietf.org/rfc/rfc3491.txt
http://www.ietf.org/rfc/rfc3490.txt
smime.p7s
Description: S/MIME cryptographic signature
