No, more like factor deciding if room can connect to another.

Let's have an example. There are few rooms with different environments in that

1 - It's a simple grassy plain
2 - A forest
3 - Cave
4 - A meadow
5 - Hills
5 - Mountains
6 - Castle grounds
7 - Castle entrance
7 - Tower
9 - Castle hall
10 - Throne room

Since plains (disp. 1) can go well with a forest or a cave, it can even connect to a meadow without any jarring results, it gets disposition of 1. Meanwhile, it'd be bad if it'd connected to e.g. Throne room, but with difference between disposition of throne room and plains higher than 3 that won't ever happen.

Now more interesting case: Caves (disp. 3). It can go well with plains, forest, meadows, heck, it can even happen on hills, mountains or even near castle grounds. Hence it has disposition of 3. Works similarily for the rest.

Because of this system I don't have to invent algorithms that says what goes well with what or make quadrillion table fields, just plain simple math. Cleaner solution IMO. And if something is connecting where it shouldn't, I just need to adjust single numeric field.

As for disposition of 0... well that's kinda special case. Those rooms are designed as adventure's start. You certainly don't want to enter room with description of "You wake up on some grassy plain", hence they won't generate ever, except as first room (which will be closed after you exit it, dunno lore details for it yet, but it will happen).