501 – Adverse Possession; Defined.

§ 501. Adverse possession; defined. For the purposes of this article:
1.  Adverse possessor. A person or entity is an "adverse possessor" of
  real property when the  person  or  entity  occupies  real  property  of
  another  person  or  entity  with  or  without  knowledge of the other's
  superior ownership rights, in a manner that would give the owner a cause
  of action for ejectment.
2. Acquisition of title. An  adverse  possessor  gains  title  to  the
  occupied real property upon the expiration of the statute of limitations
  for  an  action  to recover real property pursuant to subdivision (a) of
  section two hundred twelve of the civil practice law and rules, provided
  that the occupancy, as described in sections  five  hundred  twelve  and
  five  hundred  twenty-two of this article, has been adverse, under claim
  of right, open and notorious, continuous, exclusive, and actual.
3. Claim of right. A claim of right means a reasonable basis  for  the
  belief  that  the  property belongs to the adverse possessor or property
  owner, as the case may be. Notwithstanding any other provision  of  this
  article,  claim of right shall not be required if the owner or owners of
  the real property throughout the statutory period cannot be  ascertained
  in  the  records  of the county clerk, or the register of the county, of
  the county  where  such  real  property  is  situated,  and  located  by
  reasonable means.