In ArcGIS Desktop 9.3.1, when connecting to a WMS layer, the server sends to ArcGIS the supported CRSs (coordinate reference systems) as a list of EPSG codes.
I wonder how ArcGIS (ArcMap and ArcCatalog) recognize the coordinate reference system name and related parameters for each EPSG code in the list sent by the server, because I need to add one missing EPSG code -> coordinate reference system correlation in ArcGIS in order to workaround a bug that occurs in the following scenario:
when the server returns an EPSG codes list in which the first EPSG code is not recognized by (does not match any coordinate system name known by) ArcGIS
[EPSG list returned by the server in the GetCapabilities command replay]
<CRS>EPSG:6706</CRS> <CRS>EPSG:4258</CRS> <CRS>EPSG:25832</CRS> <CRS>EPSG:25833</CRS> <CRS>EPSG:25834</CRS>
[Layer Properties / Source / Data Source excerpt from ArcMap]
Supported Coordinate System(s): EPSG:6706 - EPSG:4258 - GCS_ETRS_1989 EPSG:25832 - ETRS_1989_UTM_Zone_32N EPSG:25833 - ETRS_1989_UTM_Zone_33N EPSG:25834 - ETRS_1989_UTM_Zone_34N
then ArcMap fails to draw the layer, even changing the data frame coordinate system in one of the others (both from the Data Frame Properties or from the Change Coordinate System dialog).