Entries in this table allow the use of simpler or descriptive names that you may use to identify libraries. Once an alias has been set up in this table, you may access that library using the alias. In the example above, there are three entries for MAINLIB. The first of these entries is echoed back on the Identification screen, once a library has been selected. The remaining entries provide alternative library names that may be entered on the library selection field to avoid the need to enter long library names.
Libraries may also be identified by DDNAME or DTFNAME, depending upon whether you are working in an MVS or VSE environment. You may also enter a number to access the appropriate library in your library authorization list in the Application Control Table.