I've heard of "Alpha Delt" for ADPi, "Kappa Delt" for KD, and "Alpha O" for AOPi.

I completely agree. I've always wondered why we called Delta Sigma Phi, DSP; Tau Epsilon Phi, TEP; and one of our locals Alpha Theta Beta, AOB.

To me Phi Sigma Sigma was always Phi Sig. And Sigma Sigma Sigma was always Tri Sig. Sigma Delta Tau was SDT. Sigma Alpha Mu was just SAMMY. Nothing outrageous, I guess!

At GT, we have Phi Kappa Psi, Phi Kappa Tau, Phi Kappa Theta, and Phi Kappa Sigma. The first two go by "Phi Psi" and "Phi Tau," respectively, but the latter two argue over who has more of a right to call themselves "Phi Kaps." Personally, I've always referred to Phi Kappa Theta as the "Phi Thetas," because there's no one else with whom they could be confused. You can't really shorten Phi Kappa Sigma's letters any other way without confusing them with another group (such as Phi Sigma Kappa, who we also have on campus)...plus they're older, both nationally and on our campus, so I figure they have more of a right to the term.

I'm considerably biased though, so whatever. :p

At my undergrad campus, we had girl and boy Phi Sigs. Usually we'd say Phi Sig for Phi Sigma Sigma, then just "boy Phi Sigs" for the fraternity. And then Alpha Xi Delta was known as AZ. I've heard them called AZD everywhere else since, never AZ.

Some of the older ASA chapters in the Midwest go by Alphas, but I think they're at schools that don't have AST (we are on many of the same campuses). Picking one of those to be "Alphas" would be way too confusing.

Why not Skulls for PKS? That's their national nickname.

Alpha Sigma Phi is usually nicknamed 'Alpha Sig'. In some campuses where there are no Sigma-named fraternities or sororities, they sometimes go by 'Sigs'.

Re: the 3 above, when I was at Penn State, AST wasn't there (I think they're there now), but we still called Alpha Sigma Alpha "ASA"; used "Skulls", and in fact, I don't think I ever knew what their real greek letters were when I was undergrad; and we definitely used "Alpha Sig" not just Sig when I was there.

ASA is also known as the Alpha Sigs on some campuses.

What are they usually known as?

They're at Behrend & Altoona but not Main. EWalk - ASA & Alpha Sigs are our usual nicknames - Apples & Alphas are the odd local ones (as per the OP in the thread).

Alpha Xi Delta = Alpha Xi's or A Xi D's
Gamma Phi Beta = Gamma Phi's or G Phi B's

Pi Kappa Phi = Pi Kapps
Sigma Nu
Sigma Pi
Tau Kappa Epsilon = Tekes
Kappa Sigma - Kappa Sigs

We also have a local, Sigma Chi Epsilon, which goes by SigEp, that was started by two initiated brothers from a chapter of Sigma Phi Epsilon. The plan, of course, is to affiliate. I'm not sure where they are in that process yet, though.

NPHC groups - not sure what their nicknames are, but we had delta sigma theta, zeta phi beta, alpha phi alpha, phi beta sigma, and kappa alpha psi if I remember correctly.

Alpha Xi Deltas were always called Fuzzies. It took me the longest time to remember thier greek letters because we never called them anything but Fuzzies. They even gave their new members bags that had "Fuzzie" printed on them.

Also, Lambda Chi Alpha was sometimes called "Choppers".

Sigma Alpha Mu was called "Sammy".

We had Sigma Phi Epsilon and it was pretty even on calling them SigEp's and SPE's. Either way worked (and since my husband is one and uses both as well, they are interchangeable to me).

The only other non-standard one for us, would have actually been for Phi Mu. It's not a totally widespread thing even on the campus, but you'll hear "QM's". One of the very well respected English professors always called us "those QM's all over campus", because if you weren't familiar with Greek letters, Phi could be Q-ish. He obviously knew what it was, but liked to kid around with us.