Allocations? I'll Go First...

We use them for open caption/ASL seating.

We use them for ASL seating and our 22for22 discount seating

We use them for Students, Senior Rush, Bert's Tix (a free ticket for students), Fan Clubs, and groups that want to pay separately but sit together (and want to go online to pay without having to call the ticket office). :)

For our University events that we host where they only want 100 seats for Student use; 200 seats for Staff to use; and the remainder of the house to be sold to the public. We have different MOS and Offers associated with different allocation codes.

Sometimes VIP seating 

Hi Jeremy,

We have a second instance of TNEW that we use specifically for our youth program, and that's where we use allocations regularly throughout the season.
Other than that, we use them very occasionally for certain special offers, and Rush tickets. We try not to use allocations too often, because they're not easy to maintain or to report on.

special member ticketing

Student tickets (once they've done web auth with their ID, they have access to their allocated seats) and for our high level members (once they log in to their account, they have access to their allocated seats).

Would love to hear more how web auth works.

Unfortunately, all I know is we have it, not how it works :( 

Thanks for the input everyone! I was trying to make a point as well as crowdsourcing ideas. 

We do something similar, using a birth date attribute, which is tied to a constituency. 

Staff Comps, any discounted/promotional tickets that require a cap on the number sold, subscriber priority seating and member priority seating. I think that's it

We use them for staff comps/discounts, large groups, and special promotions limited to certain areas of the theatre.