Mass. Gen. Laws ch. 217, § 13: Temporary register

Section 13. Upon the death, resignation, removal or absence of the register, if there is no assistant register, or if he also is absent, the judge shall appoint a temporary register to act until a register is qualified, or until the disability is removed. Such temporary register shall be sworn before the judge, and a certificate thereof, with his appointment, shall be recorded with the proceedings of each court in which he acts.