[Magnettica]

If it's bare I've never had to identify it in white tape. That's a little ridiculous if you ask me. However, they DO NOT want you to use red tape for identifying conductors on a single phase service under any circumstances. I worked for one EC that wanted both ungrounded conductors identified so we did this by marking one of the conductors with blue tape. Also, I believe some SE cable contains a red stripe which is acceptable.