- From: Henri Sivonen <hsivonen@iki.fi>
- Date: Mon, 19 Nov 2007 14:07:36 +0200
- To: "public-html@w3.org List" <public-html@w3.org>
Quoting the spec: > The type attribute gives the MIME type of the linked resource. It is > purely advisory. The value must be a valid MIME type, optionally > with parameters. [RFC2046] For attributes that take "a valid MIME type, optionally with parameters", the spec references RFC 2046. I think this normative reference doesn't meet the level of quality expected of HTML5. First, the syntax spec is awfully fragmented. First one has to follow a normative reference to RFC 2045. Then one has to look up additional rules from the future from RFC 2822. Moreover, the syntax doesn't define the syntax for MIME types as such. Instead, it defines the entire Content-Type header for Internet email. The syntax for the entire header is gratuitously complex: white space is allowed between tokens in surprising places and there's even syntax for comments hidden in the specs! Preliminary evidence from #whatwg suggests that the full syntax is not interoperably implemented in the browser context. Also, the requirement for the MIME type to be "valid" is problematic, because the registration mechanism is dysfunctional. Requiring conformance checkers to know about the IANA registry for e.g. language tags is feasible (and implemented :-). However, it would be unhelpful to flag unregistered MIME types as HTML5 conformance errors, since unregistered types are commonly used interoperably on the Web. It seems to me that the spec should refer to section 3.7 of RFC 2616 instead. I also suggest not implying that HTML5 conformance depended on the IANA media type registry. -- Henri Sivonen hsivonen@iki.fi http://hsivonen.iki.fi/
Received on Monday, 19 November 2007 12:07:49 UTC