Massachusetts Constitution Amendments Art. XLVIII, Init., Pt. II, § 3

Such petition shall first be signed by ten qualified voters of the commonwealth and shall be submitted to the attorney-general not later than the first Wednesday of the August before the assembling of the general court into which it is to be introduced, and if he shall certify that the measure and the title thereof are in proper form for submission to the people, and that the measure is not, either affirmatively or negatively, substantially the same as any measure which has been qualified for submission or submitted to the people at either of the two preceding biennial state elections, and that it contains only subjects not excluded from the popular initiative and which are related or which are mutually dependent, it may then be filed with the secretary of the commonwealth. The secretary of the commonwealth shall provide blanks for the use of subsequent signers, and shall print at the top of each blank a fair, concise summary, as determined by the attorney-general, of the proposed measure as such summary will appear on the ballot together with the names and residences of the first ten signers. All initiative petitions, with the first ten signatures attached, shall be filed with the secretary of the commonwealth not earlier than the first Wednesday of the September before the assembling of the general court into which they are to be introduced, and the remainder of the required signatures shall be filed not later than the first Wednesday of the following December.