The list of Volsers is displayed when you press Prompt (F4)
from the VOLSER field when specifying a data set:
For a Personal System Definition
In the Files view
On the Data Take-Up panel
The VOLSER List is used to specify up to 16 volume serial numbers
when the SMF data set spans more than one volume. The VOLSERs are
listed in the JCL in the same order as they are specified here.