Implementation of the trading-up principle necessitates the classification of biodiversity according to a measure of its conservation significance. In the biodiversity offset pilots in England, biodiversity is classified according to its conservation distinctiveness and offsets must contain habitat in the same or higher distinctiveness band as the loss site. The Wetland Mitigation Policy in Alberta, Canada allows for both trading-up and trading-down through a system of replacement ratios that “seek to provide an incentive to avoid the loss of high value wetlands” (Alberta Government, 2013). The system requires categorisation of the development site’s wetland into one of four value bands, it then offers a discount to the size of the required compensation if it is of greater value than the development site and increases the size of the required compensation if it is of lesser value (Table 4.3).