I'm running WMS service, that corresponds with OGC standard on WMS 1.3.0 - Queryable WMS "conformance class". It supports both mandatory requests - GetCapabilites and GetMap - and also optional request getFeatureInfo.
I was testing it with requesting the service by the method GET and I wanted to test it via POST request as well, but unfortunatelly, I wasn't able to create proper XML requests, because I haven't found any XSD schema on WMS requests. All I have found is XSD on capabilities (which deals with proper form of GetCapabilites document) and XSD on exceptions (which deals with exceptions format to be machin readable).
That forces me to think, that there is no possibility to request (properly) WMS service by POST request, or is there?