Of course I myself prefer a "fraternity" instead of "frat". I think all of the explanations are correct, and I just want to add a thing. It seems that "frat" is a degretory (sp?) term, and the comparison of this is "recruitment" instead of "rush". "Recruitment" sounds more professional than "rush".
I know the NPHC still use "frat" or "soror" or "rush", but I think they will change sometime in the future.
So I would appreciate people that use the respectful term of "fraternity" than frat. Even I have to explain this to our own alumni.
Just my .02 cents
