File Access Exit

The file access exit is entered after positioning to a requested data set if the volume is not RACF protected and if the accessibility field in the HDR1 label contains:

an ASCII uppercase letter from A through Z for Version 3 tapes or
an ASCII uppercase letter from A through Z, a numeric 0 through 9, or special characters !*"%&'()+,-./:;<=>?_ for Version 4 tapes.

The exit is also entered when a data set is written to an output volume if the first character of the JCL ACCODE keyword is one of the characters listed in the previous paragraph for a Version 3 or Version 4 tape.

The exit can either accept the data set or reject the volume, issuing one of the following return codes:

Return Code: Description
X'00': Use data set
X'04': Reject volume (set by IBM-supplied exit)

The file access exit can reject a volume that was accepted earlier by the volume access exit.