Period rules are used to set up and define various kinds of period definitions that are frequently used in N-OC. The most typical example of this is of course the roster period or crew schedule.
(Note: Later on this function will also be used for crew requests)
Once the rules have been created, the periods can be quickly and easily added in the Periods dialogue.
Notice that you can (optionally) create different period definitions using the filter option.
Editors > Calendar > Periods
Roster Revisions Concept