If that is inaceptable, why not just call it simply a formal event, and conform to no set standards?
I suppose such sartorial orthodoxy is too old fashion for most...
What about "cummerbund vs. vest vs. suspenders", or "pleated + studs vs. flat + studs vs. fly front placket", or "wing collar vs. spread collar vs. point collar", etc.?
To me, all of those seem to be far more significant deviations from any sort of standard than "no vent vs. side vent vs. center vent."