CICS command restrictions

Some general restrictions apply to all CICS® commands that access user data.

The program must be in primary addressing mode when invoking any CICS service. The primary address space must be the home address space. All parameters passed to CICS must reside in the primary address space.
If your program uses access registers, CICS preserves only access registers 2 through 13, because CICS code can use access registers 0, 1, 14 and 15 for z/OS® macro calls.