Return codes not associated with a specific command

-3: Exec not found or unrecognized command.
-4: User not an authorized user, or EXEC not allowed to use authorized commands.
-5: TWA size was not specified, or TWA size specified was less than 4 characters in length for this CICS transaction definition.
-6: REXX/CICS started with a CICS LINK and less than 16 characters provided in the communications area. Or REXX/CICS started with a CICS XCTL and either the communications area does not contain an MVS SIB type 1 control block, or the communications area length is less than 16 characters.
-99: Internal error