The RECEIVE data set decryption exit (INMRZ13 or INMRZ13R) receives control immediately after RECEIVE prompts the user for REPRO command options for deciphering an incoming file, and immediately before RECEIVE calls the Access Method Services REPRO function to decipher the file. The exit can:

• Examine and, if appropriate, change the options the user specifies. If RECEIVE is to do the deciphering, it builds the REPRO command after the exit returns, using any changes the exit makes.
• Invoke decryption processing itself. The exit is passed all the controls and ddnames that RECEIVE uses for decryption processing.
• Decide that decryption is not necessary, and prevent RECEIVE from doing it.