ODM2 Taxonomic Classifier Type Controlled Vocabulary ODM2 Working Group A vocabulary for describing types of taxonomies from which descriptive terms used in an ODM2 database have been drawn. Taxonomic classifiers provide a way to classify Results and Specimens according to terms from a formal taxonomy. Soil horizon A taxonomy containing terms describing soil horizons. Soil See http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/planners/?cid=nrcs142p2_054184.