Final register contents

The exit routine must leave the register status as follows:

Register 1:

Address of the USERVAR exit parameter list with modified values in the USERVAR parameters

Registers 2–14:

Restored to entry contents

Register 15:

Return code

X'0': Processing successfully completed.
X'01'–X'4F': The session request has failed; the USERVAR exit remains active.
X'50'–X'7F': Reserved
X'80'–X'EF': The session request has failed; the USERVAR exit is deactivated.
X'F0'–X'FF': Reserved