Kappa Kappa Psi and Tau Beta Sigma allow members of NPC/NIC/NPHC groups to joint. There have been many KDs from my chapter who belonged to one or the other of these 2 groups.

Found something interesting this morning in terms of mutual non-membership among Professional Fraternities.

At least as of 2001, Theta Tau Professional Engineering Fraternity had the following on its "Competitive List", which means that dual membership is not allowed:
Alpha Chi Sigma (chemistry)
Alpha Omega Epsilon (engineering sorority)
Alpha Rho Chi (architecture)
Kappa Eta Kappa (electrical engineering)
Phi Sigma Rho (engineering sorority)
Scarab (architecture)
Sigma Beta Epsilon (engineering sorority)
Sigma Phi Delta (general engineering)
Sigma Rho (mining, geology, metallurgy)
Triangle (general engineering, science, & architecture)

Sigma Alpha Iota has membership exclusivity policies with three other fraternities only: Delta Omicron, Mu Phi Epsilon, and Phi Beta. If you're a woman and a member of a sorority/fraternity other than one of those three, we welcome you with open arms. Our current National President is a sister of an NPC organization, as is at least one of our Regional Officers. One of the sisters in my collegiate chapter is also a Delta, as are some of the sisters from other chapters in our province/state. And, of course, I have sisters in SAI who are also sisters and brothers of Tau Beta Sigma and Kappa Kappa Psi.

I'd love to see the membership exclusivity diagram among the National Interfraternity Music Council...

As far as I can tell, its something like this:
http://i.imgur.com/gKzlMVu.jpg

TBS/KKPsi elaboration - If you were initiated into TBS and you transfer to a school that doesn't have TBS but does have KKPsi, you can't be an Active Member but you can be an Associate member. It also works if you were Active KKPsi and transfer to a school that only has TBS.
* Sources: (TBS/KKPsi)

I know that Business Fraternities (for example Delta Sigma Pi) have many members who are also initiated into NIC/NPC chapters. Seems very common.

So to boil it down, you can be Initiated as a student into *one* of ΚΚΨ/ΤΒΣ and *one* of the other five (with a few special cases).

I did this. Kind of.

Here is what happened. I was recognized as having Prodigious Mind Syndrome, at a very young age. I got to go to a fancy college, and, earned an advanced degree(a couple, actually) when I was only around 3, or, 4. So, whichever society I joined, on account of my ancestry, was just at that college.

Then, when I was around 10, or, 11, I had to go, again, to a different college, to prove that my earlier degrees were no fluke. Easy, peasy, lemon-squeezy. That was easy as. So, I joined a fraternity there, based on my ancestry, again. I did this, again, a few years later, around age 16, and, joined a different fraternity. They had the same public letters, but, it was a completely different fraternity. This is on purpose. No two are the same.

So, I had the opportunity to go, again, at a normal college age, and, wanted that experience. Well, when I got to that campus, all, except one, of the fraternities, there, were notebooked. So, instead of joining the local fraternity which had the same public letters as the other fraternity I joined, I opted to join a different one, one that was just being started.

This is fine, because, notebooked orders are imitation orders, at best. Not real fraternities, not real orders of their "parent" organization, and, typically, filled with total asshats who give Greek Life a bad name.

So, anyway, this colony gets initiated, and, they go all out. They have a mock ceremony, for everyone, and, then a private ceremony, for their "real brothers." I found this out later.

Well, I quit this "fraternity", transferred (for the first of 27 times), re-joined the second fraternity I joined (being older while pledging changes the experience, completey. I was regular brother, not the younger brother.) So, anyway, both national organizations were made aware of these incidents.

This is allowed. If you joined a gypsy fraternity, you can still join my fraternity, if you qualify. Also, if you were from a notebook order, you can join, because, notebooks fail to fully initiate their brothers.

If anyone remembers the name of the fraternity (I thought) I joined, and, from which I demitted, I hope he will keep it a secret.

I am, and, remain, a brother of the Sigma Chi Fraternity.

In Hoc Signo Vinces.

(I figured this one long post would be better than making a new thread. I was planning to reveal this, anyway, but, found this thread.)

Notebook? I have no idea what all that means.

Alpha Phi Omega, back when it was all male. You could also join an IFC group, although it apparently did not usually work out. From what I'm told.

None of this makes a damned bit of sense. I seriously call bull$hit.

Leslie Odom Miller is an NPC member? Which one? I know she's a member of a band Fraternity - I can't remember if it's KKPsi or TBS.

Yup! Leslie is a Tri-Delta. When she was the speaker for Rho A/B Province Day in 2015, when Epsilon Chi at Mississippi State hosted, after the day's festivities had officially ended a pretty large group of us went out to eat at a local Mexican restaurant and she came along as well. There was actually a group of Mississippi State Tri-Deltas there at the same time and she said hello to them as their sister too! I remember already knowing she was NPC affiliated, and I think I recognized that they were there before even going into the restaurant because of the decal on one of the vehicles outside. We sat in the same part of the restaurant that the Tri-Delta girls were already seated in, which made it easy for her to do that.

Being in both Alpha Phi Omega and a Social Fraternity goes back *all* the way to the beginning. Of the 14 founders, 8 were active brothers of Sigma Alpha Epsilon, 5 were active brothers of a local social fraternity called Krescents (that a year later became a Kappa Delta Rho chapter) and 1 was an independent and all as far as I know stayed active in their social fraternity as well. Not sure when the first occurence of joining Alpha Phi Omega first and then joining a social, but I'd bet *quite* early.

Whether A Phi O membership + social GLO membership varies widely from campus to campus, and also from person to person.
(Even if it's super fine on your campus and you consistently blow off one for the other, it's not going to work.) But then again, that's true in any case of dual membership.

I think you dropped the word "works" before varies, but I agree on the principle. I'm talking about the rules and history of the organization, not whether it is going to work for one particular student at one particular school. My degree is a bachelors in math, not a doctorate in Psych. :)