So, my brother just had a small zombie siege and experienced the age-old Boatmurdered problem of having an object stopping a defensive door from closing. It's relatively easy to clear debris from doors these days with a garbage dump and all, but it still got me thinking about forbidding doors in general. My thought was that if we made forbidding a door an actual job, as in a dwarf would need to approach the door and lock it manually, it would be simple to have the dwarf doing this move whatever is blocking the door as part of the job. It would also make the whole process somewhat more believable than having the door simply lock itself at the whim of an invisible overseer.
Now, I'm sure this would make some things that require many forbidden doors, maybe some megaprojects of some sorts, rather more difficult, so perhaps one could even make "forbidding" and "locking" different functions. Forbidding would tell dwarves that they shouldn't go through the door, but leave it accessible by hostile entities who don't care about your stupid rules. Locking would prevent the door from being opened by dwarves, hostiles, levers, anything.
If locking were to be a separate function, then that brings up a new question: do all doors have locks? As in, will doors need to have "lock" mechanisms applied to them by mechanics in order for them to be lockable? and would all dwarves have keys, or simply be able to lock them with a slide-bar or latch of some sort? If locks are separate, then perhaps there could be locksmiths as an additional mechanic labor, and if not all dwarves have keys, then perhaps there could also be a new "key-keeper" noble.
Just some little musings on the subject of forbidding doors. Thanks for whatever attention you give them.