A petition provided for in part 2 of this chapter or a resolution provided for in 13-28-301 for an election must: (1) embrace only a single comprehensive subject; (2) set out fully the ordinance sought, the ordinance to be amended and the proposed amendment, or the ordinance to be repealed; (3) be in the form provided by this chapter; and (4) contain transition provisions if the measure changes terms of office or forms of government.