This step is optional and independent of all other installation steps. It can be performed at any time after the basic FOCUS system is installed.

To install user exits, such as the Usage Accounting and Data Set Naming Enforcement Exits, you write your own code and link edit it into the basic CORFOC module. User Exits describes the exits and the required linkage editor instructions.

You can change certain FOCUS defaults, including:

• The default space allocation table for work files (IBITABLA).
• File naming conventions (DSNTAB).
• The list of commonly executed TSO commands (TSOTAB).

Customizing FOCUS contains detailed instructions for changing these.