Missouri mandates four types of school bond and tax elections. First is to issue new bonding for capital improvements and new construction and also if a school district wants to exceed its debt limit known as a debt ceiling. Also, elections are required if a school district wants to exceed a basic operating levy. The basic operating levy and the debt ceiling levy differ as the debt ceiling is a limit on all outstanding levies in a school district. Lastly, if a school district wants to revise a existing levy to increase or decrease it, a Proposition C referendum is mandated. Proposition C is protected by the Missouri Constitution. There are tough super majority requirements as a bond issue requires a four-sevenths vote (57.15%) while any referendum involving exceeding the levy cap, debt ceiling levy, or a Proposition C levy referendum requires a two-thirds super majority vote (66.7%) for approval. Missouri is one of a few states that requires super-majority approval from the voters to approve a ballot measure related to school finance.