Section 1127. Condition precedent to employment

a. Notwithstanding the
  provisions of any local law, rule or regulation to the  contrary,  every
  person  seeking  employment  with  the  city  of  New York or any of its
  agencies regardless of civil service classification or status shall sign
  an agreement as a condition precedent to such employment to  the  effect
  that  if such person is or becomes a nonresident individual as that term
  is defined in section 11-1706 of the administrative code of the city  of
  New York or any similar provision of such code, during employment by the
  city,  such  person  will  pay  to  the  city  an amount by which a city
  personal income tax on residents computed  and  determined  as  if  such
  person  were  a  resident individual, as defined in such section, during
  such employment, exceeds the amount of any city earnings  tax  and  city
  personal income tax imposed on such person for the same taxable period.
    b.  Whenever any provision of this charter, the administrative code of
  the city of New York or any rule or regulation promulgated  pursuant  to
  such   charter   or  administrative  code  employs  the  term  "salary",
  "compensation", or any other word or words  having  a  similar  meaning,
  such terms shall be deemed and construed to mean the scheduled salary or
  compensation  of  any  employee of the city of New York, undiminished by
  any amount payable pursuant to subdivision a of this section.