Scheduling End-Dated Units
Non-music units may have start and end dates and also start and end times. This can minimize the need to move promos (for example) into and out of the category during the campaign run. Say you have a promotion running from the 1st to the 10th. You've recorded a dozen different promos; some running every day but others running only from the 1st to the 5th, others from the 4th to the 7th and three of them to be scheduled only in the evening hours. You can handle this with just one category with the dozen promo cards in it and that one category is all that's needed for the format clocks that will be active during the campaign. Here's a two minute video about how it's done.
Now, about the category rule "Do not require this category to be scheduled" that's seen in the video. All the eligible units will always be scheduled as they should be. The setting only tells Music 1 that it can leave the category slot unfilled if there are no qualified tracks. If that happens, if the slot is unfilled it does not affect playout at all. The category name will still appear in the editing window, but nothing about it will be included in the playlist that's delivered to automation.