In previous releases, you could create user-specific master data exits, but you had to directly modify the program for master data administration in order to activate the exits.
As of Release 3.0, it is now possible to perform master data exits using the function CMOD. The corresponding enhancement is called GLX_MD01. The function is also described there.
You can also use existing exits; to distinguish the new exits from existing exits, you must name a new exit with =Uxx instead of with =xx.