Section 6. Nomination of candidates for town meeting members to be elected under this chapter shall be made by nomination papers, which shall show clearly whether he has been a former town meeting member, and, if an elected incumbent of such office, that he is a candidate for re-election and shall bear no other political designation. Such papers shall be signed by not less than ten voters of the precinct in which the candidate resides, shall be filed with the town clerk at least ten days before the election or, in towns which have accepted section one hundred and three A of chapter fifty-four, within the time provided by section ten of chapter fifty-three. They shall be submitted to the registrars of voters and shall be certified in the manner provided in section seven of said chapter fifty-three; provided, however, that any town meeting member, including any town meeting member in office under the provisions of a special statute under which such town is operating immediately prior to the taking effect therein of the standard form of representative town meeting government provided by this chapter, may become a candidate for election by giving written notice thereof to the town clerk not later than twenty-one days prior to the last day and hour for filing nomination papers. If a town meeting member is a candidate for re-election, the words “Candidate for Re-election” shall be printed against his name as it appears on the ballot for the election of town officers; provided, that if a town meeting member who has been chosen by the remaining members from the precinct to fill a vacancy under the provisions of section nine is a candidate for election, the words “Candidate for Re-election” shall not be printed against his name as it appears on the ballot. No nomination papers shall be valid in respect to any candidate whose written acceptance is not thereon or attached thereto when filed.