1. Method of matching one set of data elements or individual code values to the nearest equivalents in another set. Also known as crosswalk . 2. Systematized Nomenclature of Human and Veterinary Medicine (SNOMED International), Volumes I through IV are used to compare terminology context or classification description principles with the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) system. This process of linking content from one terminology or classification scheme to another is called mapping . Also see crosswalk and crosswalking .