March 18 is the final day to return nomination papers for Rockport’s May 7 annual town election. A candidate needs to return the papers with the signatures of at least 37 registered voters to the town clerk’s office at Town Hall, on Broadway, before 8 p.m. on that day to be listed on the ballot. This year, voters will select candidates for Board of Selectmen, two Planning Board seats, assessor, town clerk, library trustee, School Committee, and Housing Authority. One incumbent, Selectman Frances Fleming, has announced that she is not running. Thus far, Eliza Lucas is the only candidate for the Board of Selectmen to have returned nomination papers. March 18 is also the last day for voter registration for the annual town election.