These are the rules at wieden + kennedy. Famously found in a desk drawer by David Kennedy when clearing out his stuff to leave his old job and start the new agency. He and Dan Wieden said, 'These will do as the rules for the new place.' And it has been so ever since.
Interesting to compare with the rules of nightclub security as explained by big-haired Patrick Swayze as Dalton, the world's best bouncer, in the brilliantly bad movie Road House, which I was watching the other night.  Dalton's rules are:
1. Never underestimate your opponent
2. Expect the unexpected
3. Be nice
Wise words.
The movie ends with the classic closing line, 'A polar bear fell on me.'