I agree with Wallace’s explanation :) However, I would use the terms “exterior room(s)” and “interior room(s)” and insert the following into the footnotes for the sake of clarity: “Exterior rooms can be directly accessed from the outdoors/ courtyard, offering natural light and ventilation. On the other hand, interior rooms have to be accessed through another room.”

This picture here might help : http://tieba.baidu.com/p/2062707628

Other links:
http://www2.iccsafe.org/states/virginia/Maintenance/PDFs/Cha...
http://newmarkethotel.com/room/dd-exterior/ : The exterior two double bed room features direct outside access
http://berkeleybayit.net/rooms.html : Interior Rooms (rooms that have to be accessed through another room)
http://streeteasy.com/nyc/talk/discussion/2815-help-interior... :
NYC DOB codes specify that the max depth of the room cannot exceed 30 feet from the window and all natural light/ventilation must be provided in all habitable space/rooms. That means there are 40 x 20 space in the middle which can't have access to natural light/ventilation.
How can I create an interior room and comply with the code? Is there any exception given the long & narrow fact of the space (making compliance impossible)? Is there a work-around? A friend suggested that label the room as "exercise room" but it seems to me that it will still fall under "habitable space"?