I swear, there must be a vow that all licensed electricians take before setting out to work on their own. I believe it could be summed up thus:
XXXIV. Thou shalt never affix identifying labels to any household breaker panels.
What is it with these guys? Yesterday I saw a new client, looked at their panel in the garage to try to figure out which one the back-porch light was on, and, sure 'nuf, not a SINGLE MARKING anywhere to disturb the pristine beauty of the blank box.
I guess it just isn't macho enough to actually let the poor bastard who owns the house know which breaker goes where.
(On the other hand, another client is the ultimate counter-example: both of their breaker boxes have envelopes taped to their doors, inside of which is a complete list of breakers and devices on each. But I suspect that's because one of their sons did a lot of remodeling work for their parents.)