Each initiative petition and each referendum petition shall be duplicated for the securing of signatures. The Secretary of State shall design a form, subject to change, for signatures that shall be used by proponents of initiatives or referendums when collecting signatures, and each sheet for signatures shall be attached to a copy of the petition. Each copy of the petition and sheets for signatures is hereinafter termed a pamphlet. On the outer page of each pamphlet shall be printed the word “Warning”, and underneath this in ten-point type the words, “It is a felony for anyone to sign an initiative or referendum petition with any name other than his own, or knowingly to sign his name more than once for the measure, or to sign such petition when he is not a legal voter.” A simple statement of the gist of the proposition shall be printed on the top margin of each signature sheet.