N.Y. RPT Law § 497

§ 497. Construction of certain local option provisions in exemption\nstatutes. 1. Population restrictions. When an exemption statute makes\none or more options available to municipal corporations having a\npopulation within a specified range, and the governing body of a\nmunicipal corporation adopts a local law or resolution exercising such\nan option while its population is within the specified range, a\nsubsequent change in the population of the municipal corporation that\nplaces it outside the specified range shall not render such local law or\nresolution ineffective or invalid, nor shall it impair the ability of\nthe governing body to amend or repeal such local law or resolution to\nthe same extent as if its population were still within the specified\nrange. Provided, however, that this subdivision shall not apply to any\nexemption statute that expressly provides that a local law or resolution\nadopted thereunder shall become ineffective or invalid if the population\nof the municipal corporation subsequently experiences a change that\nplaces it outside the specified range.\n 2. Filing provisions. When an exemption statute makes one or more\noptions available to some or all municipal corporations, and further\nprovides that a municipal corporation adopting a local law or resolution\nexercising such an option shall file a copy thereof with one or more\nstate agencies other than the department of state, but if such statute\ndoes not expressly provide that a local law or resolution exercising\nsuch an option shall not take effect until a copy thereof is filed with\nthe specified state agency or agencies, then a failure to comply with\nsuch filing provision shall not render such local law or resolution\nineffective or invalid.\n