N.Y. Comp. Codes R. & Regs. tit. 9, § 1700.2
(a) As used in these rules and regulations:
(7) Family member shall mean a spouse, son, daughter, stepson, stepdaughter, father, mother, stepfather, stepmother, brother, or sister, grandfather, grandmother, grandson, granddaughter, daughter-in-law, son-in-law, mother-in-law or father-in-law of the tenant. Family member may also mean any other person residing with the tenant or cooperator in the dwelling unit as a primary or principal residence, who can prove emotional and financial commitment and interdependence between such person and the tenant or cooperator. Although no single factor shall be solely determinative, evidence which is to be considered in determining whether such emotional and financial commitment and interdependence existed shall be the income affidavit filed by the tenant for the dwelling unit and other evidence which may include, without limitation, the following factors:
(9) Housing company shall mean:
(10) Mutual company (cooperative) shall mean: