Massachusetts General Laws Part III. Courts, Judicial Officers and Proceedings in Civil Cases (Ch. 211-262) Ch. 215, § 42

A duly authorized attorney at law may enter his appearance as attorney for the party represented by him in any proceeding in a probate court, and all processes and notices served upon him shall have the same force and effect as if served upon the party whom he represents. Any person entering an appearance as herein provided, or in his own behalf, shall print or type his name directly below his signature thereon, but failure to do so shall not affect the validity thereof.