Each person signing a political body qualifying petition shall declare therein that such person is a duly qualified and registered voter of the state, entitled to vote in the next election for members of the General Assembly, and shall provide with such person's signature such person's residence address and county and the date of such person's signature. No person shall sign the same petition more than once. Each petition shall support the qualification of only one political body. No signature shall be valid if made more than 15 months prior to the submission of the petitions to the Secretary of State. A signature shall be stricken from the petition when the signer so requests prior to the presentation of the petitions to the Secretary of State for filing, but such request shall be disregarded if made after such presentation.