HTTP

This page is an attempt to document some discrepancies between browsers and RFC 2616 (and its successor, RFC 2616) because the HTTP WG seems unwilling to resolve those issues. Hopefully one day someone writes HTTP5 and takes this into account.

Redirects

For 301 and 302 redirects browsers uniformly ignore HTTP and use GET for the subsequent request if the initial request uses an unsafe method. (And the user is not prompted.)

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2007JanMar/thread.html#msg225

Location header

Browsers handle relative URIs and URIs with invalid characters in interoperable fashion.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2009JanMar/thread.html#msg276

Content-Location header

Browsers cannot support this header.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2006OctDec/thread.html#msg190

This has apparently been fixed by making Content-Location have no UA conformance criteria. (It's not clear what it's good for at this point.)

Accept header

Accept header should preferably be done without spaces.

(not raised, odinho: I came across a site that didn't like the spaces, the developer said he'd gotten it off php.net or stackoverflow. He fixed the site. This could be disputed.)

Requiring two interoperable browser implementations

To proof that RFC 2616 can be implemented there should be two compatible implementations in browsers.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2007JanMar/0222.html

Assume Vary: User-Agent

UAs and intermediary caches should act as if all responses had Vary: User-Agent specified since many pages on the Web serve different content depending on the User-Agent header but do not bother specifying Vary: User-Agent.

Raised: http://lists.w3.org/Archives/Public/ietf-http-wg/2012OctDec/0114.html