I am 100% with reno on this one. I actually use a pocket that is self adhesive on one side and made of clear plastic. I stick the pocket to the inside of the door, and then print out a card on glossy photo paper and slip it in. The advantages are many. One glaring benifit is that changes can be made without having to black-out an old description and write another in. That method is sloppy and not what I like to see when I go into a panel for service work.
I recently was at an old house to find a dead circuit in the panel. The guy who owned the house now was an architect, and his dad, who had died several years ago, was an old school architect as well and had bought the house new in the early 60s. The dad had drawn up a beautiful floorplan of the house on cross-section grid paper, color coded the outlets, fixtures, and other devices, and included a color coded breaker directory that matched the floor plan. He then laminated the plan and adheared the whole thing to the inside of the panel door. It was the most useful, understandable, graphically correct, and time-saving panel directory I have ever seen.
If the guy was still alive, I would have bought him the finest steak dinner in town for that stroke of genius and attention to detail.
The point is, the clearer and more detailed a directory is, the better. Remember, the guy who comes in later is just like you - trying to make a living. Why not make everybody happier and go the extra mile. The legal obligation in 408.4 is only the starting point, not the limit.
Good luck!
