I went to A&M, and the greek system there is somewhat large I suppose, so maybe I can help explain a little bit. We have 11 sororities and while I was there, rush numbers ranged from 600 to 1000.
There is an application deadline for the PNMs, and those who register at the last minute sometimes just don't get all of their stuff memorized by everyone.
The PNMs send in their high school or college transcripts, plus an information page, and a picture. We do put up pics of PNMs around the house, so that people learn who they are. We also go through the list of PNMs as a chapter during spirit week. It of course is IMPOSSIBLE for everyone to learn every single girl, but you get a really good idea. I was amazed how quickly people can learn names when they hear them over and over again for a week. Three years later, I could still hear a name and remember that the person went through rush.
Before the parties start, everyone in the chapter is matched up with a PNM who is in that party. The girls find out who they are picking up at the door, and they line up in that order (Alphabetically). The list is double checked just before the party starts, and if someone is missing or changed parties, then the girl who is supposed to pick her up inside is taken out of line.
The girls also wear nametags, so it is actually less common than you would expect for people to get out of line.
The time that it gets confusing is when a girl sends in a pic where she has long blonde hair, but shows up for recruitment with short browna hair. Haha. It's always a good idea to send in a pic that is close to what you ACTUALLY look like.
Whew, sorry for the long post. I hope that helps give you a better idea.
