That's an instruction to the tech/mechanic who's working on the car to see TSB (Technical Service Bulletin) 00-03 (which is an incomplete TSB number) before doing any work on the car. It also tells him to ignore that warning after Dec 31st, 2000, because the TSB will no longer be in effect.
That could have been put on the car at the factory as a part of some running change to address a recurring problem (that's also the purpose of a TSB).
FWIW, your car, being a 2001 MY car, was probably built in calendar year 2000, after that change was made. I tried to look up the TSB, but I couldn't find anything with a number close enough to what you've posted, which probably indicates that it has been pulled.