Content-Disposition: *sender* advice

Hi,

last week IE9RC came out, and sure enough, it has limited support for 
RFC 2231/5987 (limited in that it only supports UTF-8 (*)). See 
<http://greenbytes.de/tech/tc2231/>.

Which makes me wonder - should the spec include more advice for producers?

The current situation is:

1) Once IE9 is out, senders can rely on RFC5987/UTF-8 support for all 
"current" UAs, except for IE < 9 and Safari.

2) There is no fallback that would work both with Safari and legacy IE 
versions.

3) filename and filename* can safely be sent together (with filename 
acting as fallback), except that Firefox will still pick the wrong (see 
<https://bugzilla.mozilla.org/show_bug.cgi?id=588781> -- it would be 
great to see this finally fixed in FF5).

Given these constraints senders that really need to provide non-ASCII 
characters to "all" recipients have to do User Agent sniffing. That's 
bad, but I believe explaining the problem would still be better than 
being silent on it.

(*) Given that IE9RC only supports UTF-8, and the inclusion of 
ISO-8859-1 in RFC 5987 isn't essential anyway, should we note in the 
spec not ever to use ISO-8859-1?

Best regards, Julian

Received on Tuesday, 15 February 2011 21:34:15 UTC