The property tax base starts with monetary values that are placed on taxable property by the taxing authority. All states recognize market value (also sometimes called true value, just value, or actual value) as a standard for assessment, though not all states strictly apply that standard. Many states do not allow taxation of the full value of property, but rather apply assessment ratios to reduce values before the tax rate is applied. Some states classify property by its use, with different tax rates or assessment ratios for different classes of property.