specifically used at the service academies:
In the hall: a dub (or if you'd rather refer to her as "your dub", nonetheless still a dub); slayer material
Over the wall: a girl in town and/or girl at a neighboring college
On Call: back home, who you really only talk to via facebook/text when leave periods or long weekends are approaching, or by phone (only if absolutely necessary). usually GP (guaranteed pussy).
"dude, i have achieved nirvana, i met this girl in town last weekend and she is now the third leg of my 'iron triangle'... now i have to get working on my dirty thirty
and golden seven