2006 New York Code - Requirement Of License.

 
    §  26-182  Requirement  of  license.  It shall be unlawful to hoist or
  lower or to hang or attach any sign  upon  or  on  the  outside  of  any
  building in the city after December sixth, nineteen hundred sixty-eight,
  unless  such  work  is performed by or under the supervision of a person
  licensed as a sign hanger under the provisions of  this  article,  or  a
  person  qualified  or licensed as a sign hanger prior to December sixth,
  nineteen hundred sixty-eight, as provided  in  section  26-131  of  this
  subchapter.