Meh. Anyone ever associated with Boston college life would know the "tie-on-the-door knob" signal ... but now days, I understand they just use a condom. 8-D
When the dorm room's a-rockin, don't come a-knockin?
or
When the temporarily-assigned college-affiliated student housing sleeping quarters are presenting quasi-harmonic(*) motion, please refrain from striking the usually wooden, but sometimes likely to be metal or metal-and-wood, hinged entryway in a rhythmic, but such rhythm not necessarily in resonance with the harmonic motion of the room, fashion, in order to gain the attention of the occupants? /Harvard>
Cheers!
(*) or hormonic, actually.