ALIAS Operand

To create an alias name for a member of a partitioned data set, issue the RENAME command and:

Specify the data set name and the member name. Enclose the member name in parentheses.
Optionally, specify the data set name again.
Enclose the member's alias in parentheses.
Specify the ALIAS operand.

Example
To create AUXMEM as an alias for MEMBER1 of data set PREFIX.TEST.DATA, enter: `RENAME test.data(member1) test.data(auxmem) ALIAS` or `RENAME test.data(member1) (auxmem) ALIAS`

For more information on the RENAME command, see z/OS TSO/E Command Reference.