Sides are small parts of the script put out so they can hire & audition the people that play the guest/recurring roles. Recurring or the possiblity of it is usually in the casting notice. It also allows you to see small bits of the dialogue with the principle cast members when they interact with the people the sides are released for. The DSR has had sides on lockdown for a LONG time now. We haven't gotten them in probably 10 eps.

The final shot of last season was made public through a side about 2 months before Partings aired.