Mass. Gen. Laws ch. 156 § 33
Each stockholder shall be entitled to a certificate, in form conformable to section fifteen, which shall be signed by the president or a vice president and either the treasurer or an assistant treasurer of the corporation, shall be sealed with its seal and shall certify the number of shares, and the class thereof, owned by him in such corporation; but when any such certificate is signed by a transfer agent or transfer clerk and by a registrar and the registrar is not the same person, partnership, association, trust or corporation as the transfer agent or transfer clerk, the signature of the president or a vice president or of the treasurer or an assistant treasurer of the corporation, or both such signatures, or the seal of the corporation, or either or both such signatures and such seal, upon such certificate may be facsimile, and such certificate shall be as valid and effectual for all purposes as if signed by such officer or officers, or sealed with its corporate seal, as the case may be. Each certificate of stock, which by the agreement of association or amended agreement of association or, in the case of a corporation created by special law, by its articles of organization or by amendment is limited as to its voting rights or is preferred as to its dividend or as to its share of assets upon dissolution, shall have plainly written, printed or stamped thereon either a sufficient statement of such limitation or preference or a notification that its preferences, voting powers, restrictions and qualifications are fixed in the agreement of association or articles of organization or amendments filed in the office of the state secretary.
Mass. Gen. Laws ch. 156, § 33