To initiate indexed access (DSN order), either supply 44 bytes of binary zeros in the DSN area (to indicate the first data set name in the index) or specify the data set name that is the starting point for the index search.

The name returned in the DSN area is equal to or greater than the DSN supplied, depending on the ACCESS keyword selection.

If you specify DSNONLY=NO, CVAF returns the DSCB and argument using the buffer list provided with the BUFLIST keyword. CVAF uses the first entry in the buffer list with the skip bit set to 0 and a nonzero buffer address. You can specify the argument format by setting either the TTR or CCHHR bit in the buffer list entry to 1. If neither bit is set, CVAF returns a CCHHR argument. For indexed access, the DSCB size in the buffer list entry must be 96 bytes.

If you specify DSNONLY=YES, specify the CCHHR argument in the ARG area.

The data set name of the format-4 DSCB is in the index and CVAF might return its name (44 bytes of X'04'). The format-4 DSCB's name is likely to be the first data set name in the VTOC index.