N.Y.C. Admin. Code § 18-102: § 18-102 Uniform force.

a. The members of the department shall be divided into the administrative and clerical force and the uniformed force.

b. The commissioner, from time to time, shall prescribe distinctive uniforms, badges and insignia to be worn and displayed by the members of the uniformed force and prescribe and enforce penalties for the failure of any member of such force to wear and exhibit the same while engaged in the performance of his or her duties.