Where to find return code documentation

The following list refers to the appropriate return code documentation for all return codes that are expected in the IMS™ TCP/IP Services socket interface system.

To the client from the Listener (request status message).
See the information about the request status message (RSM) segment in z/OS Communications Server: IP IMS Sockets Guide for the format of the RSM and a description of the return codes.

Guideline: The RSM with the "IMS transaction unavailable to be started" return code, is returned when the IMS transaction previously abended or failed and the IMS transaction manager marked it as not able to be scheduled.
To the client from an IMS transaction (CSM).
The CSM is received by the client program when the transaction is successful. This message implies a successful return code. If this message is not received, the client program must assume that the IMS transaction did not complete successfully.
To the implicit IMS transaction from the IMS assist module (I/O program communication block).
See the information about the I/O PCB implicit-mode server in z/OS Communications Server: IP IMS Sockets Guide for the format of the I/O PCB and return code explanations.
To an implicit or explicit IMS transaction from TCP/IP.
See the information about error messages and return codes for IMS sockets calls in z/OS Communications Server: IP IMS Sockets Guide.
To an implicit or explicit IMS transaction from the IMS transaction manager.
For information about DL/I status codes, return codes, and reason codes, see the IMS knowledge center at http://www-01.ibm.com/support/knowledgecenter/SSEPH2/welcome.
To an implicit or explicit IMS transaction from the IMS database manager.
For information about DL/I status codes, return codes, and reason codes, see the IMS knowledge center at http://www-01.ibm.com/support/knowledgecenter/SSEPH2/welcome.