2021 New York Laws
PML - Racing, Pari-Mutuel Wagering and Breeding Law
Article 2 - Thoroughbred Racing and Breeding
219 - Advertising or Promotional Material.

§  219. Advertising or promotional material. Notwithstanding any other
  provision of law, rule or regulation nothing herein shall be  deemed  to
  authorize  the  stewards  or  the  commission  to promulgate any rule or
  regulation that would prohibit a jockey from wearing any advertising  or
  promotional  material  on  his  or  her  clothing.  The  wearing of such
  advertising or promotional material shall be  permitted  only  when  the
  owner of a horse for whom such jockey is riding provides the jockey with
  prior  written  authorization.  Notwithstanding  the  foregoing,  when a
  corporation, company or any other entity sponsors a race or race day  at
  any  franchised  corporation  or  any racing association or corporation,
  such racing association may prohibit a jockey from  wearing  advertising
  material  that  represents  a competitor of such sponsoring corporation,
  company or other entity.