N.Y. Comp. Codes R. & Regs. tit. 9, § 4041.6 – Wearing of advertising or promotional material.

(a) A jockey may not wear any clothing other than the usual helmet, silks, pants, boots and gloves nor display on such clothing any material other than:
1. (1) a logo of the Jockeys’ Guild that does not exceed 10 square inches;
2. (2) a logo of the Permanently Disabled Jockeys Fund that does not exceed 10 square inches; and
3. (3) authorized advertising or promotional material worn with permission of the stewards.
(b) Advertising or promotional material may be worn by a jockey provided such jockey has filed with the stewards and the race track in a form furnished by the commission at least 24 hours before the applicable race, a description of the advertising or promotional material to be worn with the name of the brands and sponsors and referring to a written authorization by the managing owner of the horse to be ridden which authorization is also filed.
(c) Notwithstanding the foregoing when a corporation, company or any other entity sponsors a race or raceday at the track, the track may prohibit such advertising or promotional material from being worn that represents a competitor of such sponsoring corporation, company or other entity. In this regard the track shall notify the stewards of such prohibition at least two hours before the first race of the day, and the jockey upon arrival in the jockeys' enclosure.
(d) A jockey may display the jockey’s name on the pants and the rear of the helmet, only if the name:
1. (1) is the jockey’s legal name;
2. (2) appears on any combination of the outside of the right thigh, the outside of the left thigh, the rear of the pants between the waistline and the base of the spine or the rear of the helmet;
3. (3) does not exceed 32 square inches on the outside of each thigh, 10 square inches on the rear of the pants and 6 square inches on the rear of the helmet; and
4. (4) appears in black lettering.