Hello,
recently I asked concerning the case of arguments to mailto URIs and
promised to summarise. Thanks a lot for all answers!
Everybody agrees that the hname part of the argument should be case
insensitive.
RFC 2822 does not state that fact explicitly, but says all character
literals given as quoted strings are case-insensitive. It proceeds
to specify all field names and header fields as quoted strings. As a
result, field names don't have to be case insensitive as such, but all
field names within the scope of RFC 2822 are for sure and I never heard
of a field specified differently.
By now I got a late answer from the authors of the draft, acknowledging
the field names used in the draft are meant to be case insensitive.
I suggested to state it explicitly nevertheless, because the draft
also uses the special string "body", which is not (yet) a registered
field name.
I asked:
Who will get a message resulting from the URI below and how will it
look like?
mailto:?to=user1(_at_)example(_dot_)com&TO=user2(_at_)example(_dot_)com
The answer is: The message will go to both recipients and it will contain
one "To:" field, listing both. The implementation is obviously free to
change the field name case and add a space after the colon, a fact that
should be specified clearly, too.
Sometimes things just work the way you expect them to. :-)
Michael