Mass. Gen. Laws ch. 255 § 7D
No assignment of, or agreement affecting, the rights or interest of a landlord or owner of real property, occupied by a tenant or person planting on shares, in crops growing or to be grown on such real property, or agreement for the subordination of a prior lien or encumbrance on real or personal property, shall be valid except as between the parties thereto unless and until recorded or registered as hereinafter provided. Each such instrument affecting real property shall be recorded or registered in the registry of deeds for each district in which any portion of such real property is situated, and each such instrument relative to the subordination of a prior lien or encumbrance upon personal property shall be recorded in each office where the instrument subordinated is recorded. A reference to the record of any deed or other instrument affected or subordinated contained in any instrument recorded or registered under authority of this section shall be noted upon the margin of each record of such deed or other instrument.
Mass. Gen. Laws ch. 255, § 7D