GLO Nickname as Single Letter?

[naraht]

Given a comment on the finding your letters...

Which letters of the Greek Alphabet have groups which will use just the single letter as a nickname? So for example: The "Alpha"'s have already done Probate' or the "Kappa" house is over on Elm street.


I'll take any National GLO here...

From my (failing) memory
Alpha - Alpha Phi Alpha
Beta - Beta Theta Pi (?)
Gamma - None (Fictional:Gamma Phi Gamma)
Delta - Delta Sigma Theta, Delta Delta Delta(?)
Epsilon - None
Zeta - Zeta Phi Beta , Zeta Tau Alpha
Eta - None
Theta - Kappa Alpha Theta
Iota - Iota Phi Theta
Kappa - Kappa Kappa Gamma (?), Kappa Alpha Psi
Lambda - None
Mu - None
Nu - None
Xi - None
Omicron - None
Pi - None
Rho - None
Sigma - Phi Beta Sigma
Tau - None
Upsilon - None
Phi - None?
Chi - None?
Psi - None?
Omega - Omega Psi Phi