- From: Larry Masinter <masinter@adobe.com>
- Date: Tue, 1 Feb 2011 14:54:14 -0800
- To: Karl Dubost <karld@opera.com>
- CC: Yves Lafon <ylafon@w3.org>, "Eric J. Bowman" <eric@bisonsystems.net>, "nathan@webr3.org" <nathan@webr3.org>, "ashok.malhotra@oracle.com" <ashok.malhotra@oracle.com>, Jonathan Rees <jar@creativecommons.org>, Noah Mendelsohn <nrm@arcanedomain.com>, "www-tag@w3.org" <www-tag@w3.org>
Just thinking about this more. How about two headers: content-type: content-type-verified: (I started with 'verified-content-type' but there is some belief that 'content-' headers stay associated with the MIME body and are rewritten when the content is transformed but otherwise not, while other headers are hop-to-hop or end-to-end but connected with the transmission.) these two headers SHOULD be the same. If they're the same, the receiver can rely on the content-type and must not sniff. If there's only content-type, then the sender hasn't verified the content-type and receiver MAY sniff (but only within well-known and established rules.) If they are different, then the content-type has been modified by some unaware intermediary which has modified the content-type without changing the "content-type-verified". In this case, the receiver should accept the content-type as authoritative, since the content-type transformation wasn't done unknowingly. This might give a way of introducing out-out sniffing. Again, this only works if the receivers which follow this protocol are well-deployed in the field before any senders start sending "content-type-verified". Those write recievers believe (rightfully) that they have the last word, set the standard, get to do whatever they want, so that a "processing rule" may or may not actually be meaningful. There are too many different kinds of receivers, not just browsers, but search engines CDNs, etc. A server telling them what to do with a processing rule "sniffing: opt-out" ... well, it's bound to be ignored. However, if the sender is just telling the receiver MORE information, that has different semantics. Operationally, though, this is equivalent to the other proposal. Larry -- http://larry.masinter.net
Received on Tuesday, 1 February 2011 22:54:45 UTC