Mass. Gen. Laws ch. 204 § 29
A release executed by the donee of a power releasable according to section twenty-seven, or under common law, and delivered or filed in accordance with the first sentence of section twenty-eight, shall, subject to the second sentence of section twenty-eight, be effective to release the power to the extent in such release provided, whether it in substance provides for the release of all right of the donee to exercise the power, or for the release of all right of the donee to exercise the power otherwise than in respect of a part, therein defined, of the property subject to the power, or for the release of all right of the donee to exercise the power otherwise than to or for the benefit of, in trust for, or in favor of a person or persons or class or classes of persons, therein specified, or an object or objects or class or classes of objects, therein defined.
Mass. Gen. Laws ch. 204, § 29