You're going to get a different answer from everyone. Every team has their own system of labeling bunkers, just like they have there own system for g-count, etc. Just make up your own. There's really no dead set way to do it.
The one team i play with change it every tournament that way no one knows that we know where they are at. You guys just got to figure out what works best for you. Everyone has there own terms just make something up.