This is probably a silly question, but it's been giving me a hard time for a bit now.
Is "!.com" (without the quotes) a valid JID? The definition of a JID is: A domain identifier MUST be an "internationalized domain name" as defined in [IDNA], to which the Nameprep [NAMEPREP] profile of stringprep [STRINGPREP] can be applied without failing. >From this definition, "!.com" passes all the rules. None of the prohibited tables list "!" in them anywhere (or " " <space>) as far as I can tell. IDNA does talks about LDH characters (which would means a "!" is invalid), and it talks about them in the context of having a UseSTD3ASCIIRules flag. I can't determine if I should be using this or not. Common sense says "yes" we should require this flag, but the more I read the spec, the more I think, "no". Specifically the phrase (from RFC 3490): An "internationalized label" is a label to which the ToASCII operation (see section 4) can be applied without failing (with the UseSTD3ASCIIRules flag unset). Can any of the IDNA / Unicode guru's on this list help me answer this? -- Chris Mullins