Mass. Gen. Laws ch. 60, § 87: Directions to collectors; ordinances or by-laws

Section 87. A city or town may, by ordinance or by-law, respectively, direct whether its collector shall exercise the power of sale or the power of taking to enforce the lien for taxes; and in default of such ordinance or by-law the collector may exercise either power at his discretion; but the passage of any such ordinance or by-law shall not render invalid any proceedings then pending.