...which brings us to padding. With any some_direction orientation,
            you need 6 layers of x-padding along any level-edge that the vault
            borders. For instance, if your map is ORIENT: north, you must have a
            6 deep border of rock wall (or any other kind of wall) along the
            northern, eastern, and western edges of the map.
          * "encompass": the vault completely occupies the entire level.
            Padding is needed on all 4 sides.

          ORIENT: float vaults need no padding and give a lot of
          flexibility to the dungeon generator; float should generally
          be preferred to other ORIENT: settings for new vaults.

          ORIENT: float vaults give a lot of flexibility to the dungeon
          generator; float should generally be preferred to other ORIENT:
          settings for new vaults.