In order to generate a soil map of Scotland using the WRB soil classification system, the dominant soil taxonomic unit in each 1:250 000 scale soil map units were classified according to the diagnostic criteria laid out in WRB 2007 (IUSS Working Group WRB, 2007) and following the updated procedures for constructing small scale map legends (IUSS Working Group WRB, 2010). As the intention was to produce a map at a notional scale of 1:1 000 000, the soils were classified to the level of the Reference Soil Group and two qualifiers. Boorman, D.B., Hollis, J.M and Lilly, A. 1995. Hydrology of soil types: a hydrologically-based classification of the soils of the United Kingdom. Institute of Hydrology Report No.126. Institute of Hydrology, Wallingford. IUSS Working Group WRB. 2007. World Reference Base for Soil Resources 2006, first update 2007. World Soil Resources Reports No. 103. FAO, Rome. IUSS Working Group WRB. 2010. Addendum to the World Reference Base for Soil Resources: Guidelines for constructing small-scale map legends using the World Reference Base for Soil Resources. FAO, Rome. Soil Survey of Scotland Staff. (1981). Soil maps of Scotland at a scale of 1:250 000. Macaulay Institute for Soil Research, Aberdeen.