Section 17-311. Display of license or plate

a. Each food vendor shall carry
  his or her license upon his or her person and it shall be exhibited upon
  demand  to  any  police  officer,  public  health  sanitarian  or  other
  authorized officer or employee of the city.
    b. The food vendor's license shall be worn conspicuously by him or her
  at all times while he or she is operating as a food vendor.
    c.  The permit plate shall be firmly affixed to the vending vehicle or
  pushcart in a conspicuous place.
    d. Vendors issued fresh fruits  and  vegetables  permits  pursuant  to
  paragraph  four of subdivision b of section 17-307 of the administrative
  code of the city of New York shall carry upon their person  a  laminated
  or  similarly  durable  and  easily readable map, prepared and issued to
  them by the commissioner, designating those areas of the city  in  which
  they  are  authorized  to  vend. Those persons issued a fresh fruits and
  vegetables permit found to be vending from green carts and  vehicles  in
  precincts  other than those designated on their borough-specific permits
  shall be deemed to be operating  such  vehicle  or  pushcart  without  a
  permit.