The starting points for checking feedback from an APPCCMD macroinstruction are registers 15 and 0. Register 15 contains the general return code from VTAM®. Only a few values are defined for the general return code, and it gives a quick indication of whether the macroinstruction was successful. Register 0 contains either a conditional completion return code or recovery action return code. In the case of errors, it provides more detail on the cause of the error.

If both register 15 and register 0 are 0, the APPCCMD has completed or been accepted without error. If register 15 is 0 but register 0 contains X'000000B', the request completed conditionally.