HTML4 / XHTML1 allows only GET and POST in forms, now it seems like HTML5 will do the same. There is a proposal to add these two but it doesn't seem to be gaining traction.
What were the technical or political reasons for not including PUT and DELETE in HTML5 specification draft?
Best Answer
This is a fascinating question. The other answers here are all speculative, and in some cases flat-out incorrect. Instead of writing my opinion here, I actually did some research and found original sources that discuss why delete and put are not part of the HTML5 form standard.
As it turns out, these methods were included in several, early HTML5 drafts (!), but were later removed in the subsequent drafts. Mozilla had actually implemented this in a Firefox beta, too.
What was the rationale for removing these methods from the draft? The W3C discussed this topic in bug report 10671. Mike Amundsen argued in favor of this support:
It's worth reading his entire post.
Tom Wardrop also makes an interesting point (href):
The bug was eventually closed as Won't Fix by Ian Hickson, with the following rationale (href):
However, that's not the end of the story! The issue was closed in the W3C bug tracker and escalated to the HTML Working Group issue tracker:
https://www.w3.org/html/wg/tracker/issues/195
At this point, it seems that the main reason why there is no support for these methods is simply that nobody has taken the time to write a comprehensive specification for it.