Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 51, § 41

The registrars shall preserve all written applications, complaints, certificates and affidavits received by them, and all other documents in their custody relative to listing and registration, for two years after the dates thereof; provided, however, that original affidavits of registration, or microfilm copies thereof, shall be preserved and shall be deemed to be public records, except large print affidavits of registration.