On the Staff Attendance page, you'll see various types of staff attendance codes. In this example, there are two: [A] Absent and [W] Working off-campus.

If you'd like to add, remove, or modify staff attendance codes, click "Edit Staff Member Attendance Types" on the Configure page (you need to have the "Edit Staff Member Attendance Types" permission to view and use this option).

You can then add, deactivate, or modify staff member attendance types. Hover over question marks to learn more about what each attribute means. Click on the gear icon to edit, duplicate, or deactivate attendance types.

You'll see a screen like this when you add or modify an absence code:

And after saving your changes, you'll see the updates when you go back to the Staff Attendance page.