When Dispatch does a dynamic allocation to archive a dataset, there are several suffixes that it will append to the end of the DSN, depending on the media we are trying to allocate. For example:
DISP.ARCH.D20345.T001119.A01
In the above example, the "A" in the suffix tells us allocation is for a TAPE unit.
The information below outlines archive DSN suffix meanings:
A = TAPE
C = TAPE for CONDENSE output
F = TAPE for RE-CONDENSED output
O = OPTICAL
D = DASD
S = SMS