In situations where an error return code does not provide adequate problem determination information, your TP can call the Error_Extract conversation service to return detailed information about the error. Error_Extract provides reason codes and messages that describe errors in APPC/MVS conversations. If a partner system or TP sends error log information to MVS, Error_Extract can return the error log information and a product set identifier. For more information about calling the Error_Extract service, see Diagnosing Problems with APPC/MVS TPs.