docs/URL-SYNTAX: document the URL syntax curl accepts #6285
#6283 triggered my interest in writing a doc like this.
I also think parts of the CURLOPT_URL man page could be better placed in this document. Like the "security concerns" perhaps. Perhaps even all the protocol specific details - as the URL details are almost always also valid for the curl tool users and they will not read that man page. And duplicating the info in multiple places is never a good idea...