Howard Jarvis and Paul Gann were the most vocal and visible advocates of Proposition 13. Officially named the "People's Initiative to Limit Property Taxation," and known popularly as the "Jarvis-Gann Amendment," Proposition 13 was listed on the ballot through the California ballot initiative process, a provision of the California Constitution that allows a proposed law or constitutional amendment to be offered to voters if advocates collect a sufficient number of signatures on a petition. Proposition 13 passed with roughly two-thirds of those who voted in favor and with the participation of around two-thirds of registered voters. After passage, it became article XIII A of the California Constitution.