As the web doesn’t appear to have a list of registered HTTP methods I’ll make one. (RFC 2616bis will most likely define a registry for HTTP methods, but that’s a few years away still, as I understand it.)
OPTIONSGETHEADPOSTPUTDELETETRACECONNECTPROPFINDPROPPATCHMKCOLCOPYMOVELOCKUNLOCKVERSION-CONTROLREPORTCHECKOUTCHECKINUNCHECKOUTMKWORKSPACEUPDATELABELMERGEBASELINE-CONTROLMKACTIVITYORDERPATCHACLPATCHSEARCHBasically, the original HTTP methods plus a lot of stuff for WebDAV. Maybe a future version of this list will be a table and include information about whether a given HTTP method is safe, idempotent and cacheable. Didn’t need that information myself.
It seems that there a bunch of other methods floating around as well either invented by Microsoft for Microsoft products or somewhere else. The interwebs isn’t very good at providing detailed information about WebDAV unfortunately. MSDN has section on WebDAV methods which lists the following that are not in the above list:
BCOPY
BDELETE
BMOVE
BPROPFIND
BPROPPATCH
NOTIFY
POLL
SUBSCRIBE
UNSUBSCRIBE
X-MS-ENUMATTS
Elsewhere I found RPC_OUT_DATA and RPC_IN_DATA. I suspect there are more.