ยง 56. Establishment and duration of eligible lists. 1. The duration of
  an  eligible list shall be fixed at not less than one nor more than four
  years; provided that, except for lists promulgated  for  police  officer
  positions in jurisdictions other than the city of New York, in the event
  that  a  restriction  against  the  filling  of  vacancies exists in any
  jurisdiction, the state civil service department or municipal commission
  having jurisdiction shall,  in  the  discretion  of  the  department  or
  commission,  extend the duration of any eligible list for a period equal
  to the length of such restriction  against  the  filling  of  vacancies.
  Restriction  against  the  filling  of  vacancies shall mean any policy,
  whether by executive order or otherwise, which, because of  a  financial
  emergency,  prevents  or  limits the filling of vacancies in a title for
  which a list has been promulgated. An eligible list  that  has  been  in
  existence for one year or more shall terminate upon the establishment of
  an  appropriate new list, unless otherwise prescribed by the state civil
  service department or municipal commission having jurisdiction.
2. Notwithstanding subdivision one of this section,  the  duration  of
  eligible  lists established on or before December thirty-first, nineteen
  hundred ninety-six, shall be fixed at not less than one  nor  more  than
  four  years;  provided  that,  except  for  lists promulgated for police
  officer positions in jurisdictions other than the city of New  York,  in
  the  event that a restriction against the filling of vacancies exists in
  any jurisdiction,  the  state  civil  service  department  or  municipal
  commission   having   jurisdiction  shall,  in  the  discretion  of  the
  department or commission, extend the duration of any such eligible  list
  for a period equal to the length of such restriction against the filling
  of  vacancies.  Restriction  against the filling of vacancies shall mean
  any policy, whether by executive order or otherwise, which  prevents  or
  limits  the  filling  of  vacancies in a title for which such a list has
  been promulgated. An eligible list that has been in  existence  for  one
  year  or  more  shall terminate upon the establishment of an appropriate
  new list,  unless  otherwise  prescribed  by  the  state  civil  service
  department or municipal commission having jurisdiction.
3.  Notwithstanding any law to the contrary, the name of any applicant
  or eligible whose disqualification has been reversed or whose rank order
  on an eligible list has been adjusted through administrative or judicial
  action or proceeding shall be placed on an eligible list for a period of
  time equal to the period of  disqualification  or  for  the  period  the
  application  has  been  improperly ranked, up to a maximum period of one
  year or until the expiration  of  the  eligibility  list,  whichever  is
  longer.  If  an  eligible  list  expires prior to the expiration of such
  period of restoration, the name of the applicant or  eligible  shall  be
  placed  on a special eligible list, which shall have a duration equal to
  the longer of (a) the remainder of the period of restoration or (b)  two
  years. An applicant or eligible whose disqualification has been reversed
  or whose rank order has been adjusted subsequent to the expiration of an
  eligible list shall be placed on a special eligible list for a length of
  time equal to the restored period of time not to exceed a maximum of one
  year.
4.  Notwithstanding  the foregoing provisions of this section, where a
  court of competent jurisdiction has determined that an eligible list  is
  invalid,  the  court  may  order the creation of a special eligible list
  having a duration of  not  less  than  one  nor  more  than  four  years
  commencing at the time the corrected list is published.
Structure New York Laws
Article 4 - Recruitment of Personnel
Title A - Examinations and Eligible Lists
50-A - Test Validation Boards.
50-C - Discrimination Based Upon History of Cancerous Condition Prohibited.
51 - Filling Vacancies by Open Competitive Examination.
55 - Examination of Blind or Physically Handicapped Applicants.
55-A - Employment of Persons With Disabilities by Municipalities.
55-B - Employment of Persons With Disabilities by the State.
55-C - Employment of Veterans With Disabilities by the State.
55-C*2 - Acceptability of Certain High School Diplomas.
56 - Establishment and Duration of Eligible Lists.
57 - Continuous Recruitment for Certain Positions.
58 - Requirements for Provisional or Permanent Appointment of Certain Police Officers.
58-A - Requirements for Provisional or Permanent Appointment of Certain Fire Fighters.
59 - Placement of County Sheriffs' Personnel in Classified Service.
59-A - Placement of Detectives and Investigators in Classified Service.
59-B - Promotions of Supervisory Personnel of the Emergency Medical Service.
59-C - State Employment of Persons and Veterans With Disabilities Study.