The Taxpayer Bill of Rights (abbreviated TABOR) is a concept advocated by conservative and free market libertarian groups, primarily in the United States, as a way of limiting the growth of government. It is not a charter of rights but a provision requiring that increases in overall tax revenue be tied to inflation and population increases unless larger increases are approved by referendum.
Colorado example
The most well-known example of TABOR legislation is in the state of Colorado.
In 1992, the voters of the state approved a measure which amended Article X of the Colorado Constitution...