The AllowUserKeyCSA parameter was introduced in z/OS V1.8 to prevent jobs from allocating storage from Common Storage Areas subpools using user keys 8 through 15. It can be set to AllowUserKeyCSA(YES) or AllowUserKeyCSA(NO). User key CSA creates a security risk because any unauthorized program can modify it.
At z/OS 1.8 the default was ALLOWUSERKEYCSA(YES) for compatibility. Starting at V1.9, the default is AllowUserKeyCSA(NO).
How does parameter << ALLOWUSERKEYCSA>> affects CA Endevor SCM?
z/OS V1.8 and higher
Endevor does not use CSA storage for its processing, so setting of ALLOWUSERKEYCSA to either yes or no has no effect on Endevor.
Example of D DIAG command display from the z/OS console :
IGV007I 15.55.44 DIAG DISPLAY 463
VSM TRACK CSA(ON) SQA(ON)
VSM TRACE GET(OFF) FREE(OFF)