HTTP method OPTIONS
The HTTP OPTIONS method requests permitted communication options for a given URL or server. A client can specify a URL with this method, or an asterisk (*) to refer to the entire server.
Syntax
OPTIONS /index.html HTTP/1.1
OPTIONS * HTTP/1.1
Examples
curl -X OPTIONS https://example.org -i
HTTP/1.1 204 No Content
Allow: OPTIONS, GET, HEAD, POST
Cache-Control: max-age=604800
Date: Thu, 13 Oct 2016 11:45:00 GMT
Server: EOS (lax004/2813)