Hi,
Somebody put on another forum these variables with short description (I think these are the same like in the link already put by jackk)
CATLM_ODTS=1 - Disable license error messages at startup
L_WILSON_LAN=1 - Access to Wilson's spline curves
CGM_ROLLINGOFFSET=1 - Access to the Rolling Offset option in GSD
TAILLE_MEMOIRE_CHOISIE=1 - Optimize IGES export memory
CATNoStartDocument=no - Disable product at startup
CNEXTBACKGROUND = no - Disable sky background at startup
CNEXTSPLASHSCREEN = no - Disable display of planet at startup
SHOW_CST_CHILDREN = 1 - Display stresses in the parents specification tree in sketcher
CNEXTOUTPUT = console - Display Catia's logs in command windows
MM_NO_REPLACE = 1 - Associativty about replacement of components cloned with different
You can put all of them if you are going to control panel-system properties-environment variables-add new user variable.
Regards
Fernando