(1) The signatures and addresses on petitions shall be the same as the signatures and addresses on voter registration cards and, if not registered or if not required by law to be an elector, their common signature. If the elector has signed using an initial letter only in place of a name written on the registry card or using a name or the initial letter of a name that is not on the registry card, the signature may nevertheless be counted so long as the signature, taken as a whole, bears sufficient similarity to the signature on the registry card as to provide reasonable certainty of its authenticity.
(2) The signatures on protests and waivers shall be the accepted common signatures.