Mass. Gen. Laws ch. 157B § 4
In this chapter, the following words shall have the following meanings:
"board", board of directors;
"by-laws", the by-laws of a cooperative corporation as they exist from time to time;
"cooperative corporation", a corporation organized or existing under this chapter;
"limited equity cooperative housing corporation", a cooperative corporation organized and operated primarily for the benefit of low and moderate income persons, and whose equity, after allowance for maximum transfer value of its stock, is permanently dedicated to providing housing to persons of low or moderate income or to a charitable purposes;
"member", a person who holds voting stock of a cooperative corporation;
"proprietary lease", an agreement between a cooperative corporation and its stockholder for occupancy of a dwelling unit owned by the cooperative corporation;
"transfer value", the value which may be paid or received upon the sale or transfer of the stock of a cooperative corporation.
Mass. Gen. Laws ch. 157B, § 4