Originally, I was going to have basic corridors handled as a separate "layer". But while I was working on the "other symbols" installment and comparing it to the punctuation post, I decided that maybe drawing corridors as part of the room creation process isn't too difficult, especially since the process I was originally going to use would create the exact same corridors.
So: From the current start point to the offset point, draw a 10' wide corridor eastwards, with the south wall of the corridor flush with the south wall of the current room. If the word begins with a capital letter, draw the corridor northwards instead, with the west wall flush with the west wall of the current room. Either way, any overlapping parts are merged into one; if the offset is long enough, the corridor emerges from the wall opposite the start point and defines the next start point at the corridor's end.
This is in contrast to the way the Comma works in the punctuation post. Punctuation defines an exit and direction first, then extends the corridor from the exit in the appropriate direction. Thus, you can have an eastward corridor extend from the north wall, instead of the east wall. If the exit point is defined on the wall opposite the direction it is headed (so that the exit corridor would pass through the room it was leaving,) it heads towards the nearest corner instead, then turns in the appropriate direction. This makes a Comma corridor different enough from a standard corridor to add variety.
I've made a change to the way exits are handled as well. Previously, if the perimeter offset was greater than the actual perimeter of the room (5' square with a 30' perimeter offset, for example,) I went around the room's perimeter as many times as necessary. Now, however, I think I'll just stop when I've gone almost completely around the room. I have another alternative I'm considering, though.