All of the honorary naming happened in the early years of KD. I'm actually not sure exactly when we started going strictly alphabetical. Many early chapters took their designations from the locals that petitioned KD for a charter.
Earlier in this thread, Cheryl asked about KD's only chapter with a 3-letter name. This one is a good example. Rho Omega Phi chapter was named after the R.O.F. Society (a local at Judson). Similarly, Sigma Sigma chapter, Sigma Delta chapter, Phi Epsilon,...etc. were all named after the local sororities that KD absorbed.
So, I guess that's a clue for my trivia question. It's an early chapter. (and one that's still going strong!)