Restrict number of a certain game piece

I giving a try to create a module for Dual Powers.
I’m looking at the Monopoly module for ideas.
I’m wondering how they limit the number of Hotels to 12 in the module.

The easiest way is to put exactly 12 of them in the game, via an At-Start stack (or 12 at-start stacks). Don’t supply a way to delete one or create or clone one, don’t have one in a piece palette. Only supply a way to move/claim one.