§ 497. Construction of certain local option provisions in exemption
statutes. 1. Population restrictions. When an exemption statute makes
one or more options available to municipal corporations having a
population within a specified range, and the governing body of a
municipal corporation adopts a local law or resolution exercising such
an option while its population is within the specified range, a
subsequent change in the population of the municipal corporation that
places it outside the specified range shall not render such local law or
resolution ineffective or invalid, nor shall it impair the ability of
the governing body to amend or repeal such local law or resolution to
the same extent as if its population were still within the specified
range. Provided, however, that this subdivision shall not apply to any
exemption statute that expressly provides that a local law or resolution
adopted thereunder shall become ineffective or invalid if the population
of the municipal corporation subsequently experiences a change that
places it outside the specified range.

2. Filing provisions. When an exemption statute makes one or more
options available to some or all municipal corporations, and further
provides that a municipal corporation adopting a local law or resolution
exercising such an option shall file a copy thereof with one or more
state agencies other than the department of state, but if such statute
does not expressly provide that a local law or resolution exercising
such an option shall not take effect until a copy thereof is filed with
the specified state agency or agencies, then a failure to comply with
such filing provision shall not render such local law or resolution
ineffective or invalid.