The details of CAA requirements for creep marks are found in CAP562 Civil Aircraft Airworthiness Information and Procedures (CAAIP):
http://www.caa.co.uk/application.asp...e=detail&id=92
Have a look in leaflets 5-7 and 5-8.
They should be applied and re-applied by any good engineer as and when they need it (ie when faded and found on a check or when changing the tyre).
They often disappear on the tyre because most paint really doesn't like sticking to the rubber and if the aircraft is operated off grass, the grass rubs it off quite quickly.