At the time of inspection, a warning label must be attached. Brady , Panduit & others make them. At least one manufacturer supplies a label with some of their panelboards. Some of the label examples I've seen have fill in blanks for available fault current, level of protective gear required, but this information is not required by 110.16 and should not be presumed to be factual except the day the calculation was done.
I don't know what we'll do about marking meter sockets. These are furnished by the power company in our area and on the 100 amp size, there isn't very much room for a label on the front cover. I wouldn't consider the side of the meter enclosure to be clearly visible under all conditions. Even though the power company employees should know the dangers, it never hurts to give someone a reminder.
Tom
