3.2.5.4 Extensions to GET and POST

The WebDAV server SHOULD ignore the header if it receives an X-MSDAVEXT: PROPFIND header when support for the WebDAV Protocol: Client Extensions is not advertised. If the WebDAV server advertised the support for the extensions, it MUST process the command and return the properties and the file contents in the format that is specified in section 2.2.5.<24>