I inspected a panel once for an "electrician" who simply labeled it "plugs", "lites", "stove", "SD", "H2O", "furnace", "kit 1", & "kit 2". :grin:
Ever tried doing service work on a FEMA spec mobile home or park model trailer? That's what I've been doing for the last 2 years in South LA after Katrina. The guys who build these trailers are...let's see, how to best put this-MORONS!!!!!! There are only about 1 or 2 manufacturers who actually label the panel cover correctly and legibly. The rest, well, good xxxxxx luck! I've spent a couple of hours before trying to identify the correct circuit and figure out how these idiots wired the dang thing so I could fix the problems. I am a little above average on troubleshooting skills, but man, sometimes this crap blows your mind.
I use a "fox and hound" wire tracer sometimes, and once found a wire in a ceiling that went nowhere. Everything in the trailer worked, there were no shorts, but this wire was live up to a point in the ceiling and then just dissapeared. Interesting... Also once had a trailer where the range would not work. Troubleshooting showed that the wire was hot leaving the panel but dead at the receptacle. Only answer was the wire was burnt or broken. Went to purchase wire, returned and removed some of the insulation under the trailer, found that the cable had been cleanly cut right under the panel! Dryer was discovered to be the same way.
Anyway, got a little sidetracked. I prefer to write on the jacket on the romex and make a temp. panel schedule, then write it all on the perm. panel cover. I usually don't relabel individual wires in the panel itself though. No real reason, just don't in residential. Used to do a lot of industrial elect./instrumentation, where labelling was a hard, fast rule. I guess, as someone said earlier, to each their own, but think of the next guy to come along, 'cause it might be you!:wink: