I want to know what my Thoroughbred's brands mean?

My gelding is an ex-racehorse (apparently...I don't think he as a lip tattoo which apparently all racehorses a supposed to have, but anyway), I want to know what his brands mean. On his right shoulder he has 7 on top of a 2, and on the left shoulder a 9 on top of a 2. His race name was Rebel.