On entry to the security exit, Register 1 points to a list of ten full words, as shown in this diagram.

The contents of the parameter list are as follows:
Is a full word containing the address of function code F'24'.
Is set to zero.
Is the address of an 8-character field, blank-padded, containing the user ID for which information is required.
Is the address of three full words containing the session correlator and the user token (UTOKEN) associated with the user issuing the request (not necessarily the correlator for the user ID whose information is being requested).
Is the address of an 8-character field, blank-padded, containing the user ID requesting the information (or zero).
Is set to zero.
Is set to zero.
Is the address of an 82-character area into which the exit can place any error message text if the function request is denied or failed. Any text placed in this area is displayed to the user in response to the command that caused this request. If an error message is returned it must be formatted as follows:
Specifies the hexadecimal length of the message text (excluding these two bytes).
Specifies the error message text.
Limits: 80 characters
Is set to zero.
Is set differently depending on the type of exit you have:
The exit must return a completion code in Register 15 on return. Completion codes are supported as described below. Causes for rejection are identified by error message text returned in the area addressed by word 8 of the Information Call parameter list.
The return codes listed below are the only codes that are accepted in response to an Information Call. Any other return code is treated as information not available.
Indicates that information is available. Word 10 of the parameter list points to an address list that provides pointers to structured fields describing the user ID.
Indicates that information is not available. An error message should be available in the 80-character area addressed by word 8 of the parameter list.