Make wms layer groups requestable

en/ogc/wms_server.txt

@@ -1831,22 +1831,20 @@ Layer Object Metadata
   of hierarchically nested groups. This grouped hierarchy will be
   expressed in the capabilities.
 
-  WMS_LAYER_GROUP is different from the GROUP keyword in that it does not 
-  necessarily publish the name of the group in the capabilities, only the 
-  title is always published. If a layer with the same name as used in 
-  WMS_LAYER_GROUP is found it is treated as named group and if no layer with 
-  this name is found as unnamed group.
-
-  As a consequence the groups set with WMS_LAYER_GROUP can not always 
-  be requested with a GetMap or GetFeatureInfo request (see section
+  From MapServer 7.2, WMS_LAYER_GROUP is similar to the GROUP keyword in that
+  it necessarily publishes the name and the tile of the group in the
+  capabilities.
+
+  As a consequence the groups set with WMS_LAYER_GROUP can always be
+  requested with a GetMap or GetFeatureInfo request (see section
   7.1.4.5.2 of the WMS implementation specification version
   1.1.1. (OGC 01-068r2)). Another difference is that GROUP does not
   support nested groups. The purpose of this metadata setting is to
   enable making a WMS client aware of layer grouping.
 
   All group names should be preceded by a forward slash (/). It is not
   allowed to use both the WMS_LAYER_GROUP setting and the GROUP
-  keyword for a single layer.
+  keyword for a single layer. GROUP can be seen as deprecated!
 
   .. code-block:: mapfile