[Gvsig_english] General Question: Adding WMS Server -> choosing the right/best EPSG

[Marcel Schoolmeesters]

Hey,

anybody who can help me with choosing the right EPSG?

I know there are different EPSG, each for different coordinate system 
and projection. But when many SRS are selectable, which is the right / 
best one? and what's the reason for choosing it? e.g. the gvSIG Mobile 
Default WMS: 
http://www.idee.es/wms/PNOA/PNOA?Request=GetCapabilities&Service=WMS ... 
why are so many EPSG listed?


Best regards,

Marcel