Massachusetts General Laws Part II. Real and Personal Property and Domestic Relations (Ch. 183-210) Ch. 185, § 58

Every conveyance, lien, attachment, order, decree, instrument or entry affecting registered land, which would under other provisions of law, if recorded, filed or entered in the registry of deeds, affect the land to which it relates, shall, if registered, filed or entered in the office of the assistant recorder of the district where the land to which such instrument relates lies, be notice to all persons from the time of such registering, filing or entering.