Mass. Gen. Laws ch. 51 § 51
To every person registered under section fifty the registrars shall issue a certificate, similar to that provided for in section fifty-nine, entitled "Supplementary Registration -- Specially Qualified Voter", and referring by chapter and section number to this section and section fifty. Upon presentation of such certificate to the presiding officer at the proper polling place, or, in the case of an absent voter, if such certificate is attached to the voting lists, such person shall have the same right to vote as any other registered voter. Except in the case of an absent voter, after such person has voted, the presiding officer shall attach the certificate to the voting list and it shall be considered a part thereof, and shall be returned to the registrars and preserved in accordance with law.
Mass. Gen. Laws ch. 51, § 51