Communication from the exit programs to CICS® VR occurs through the parameters.
All communication between CICS VR and the exit programs is through parameters. When the archive utility or the log stream copy utility calls an exit, register 1 points to a parameter list containing the addresses of the parameters. The parameter list is an area whose length depends on the number of parameters to be passed. For each parameter, it consists of one fullword containing the address of the parameter.
Each exit has a different parameter list. You can find these lists and descriptions of the parameters, in the exit descriptions starting on page Precopy exit: process a copy of the log record.