This case-sensitive code system http://va.gov/terminology/medrt defines codes, but no codes are represented here

 <status value="active"/> <experimental value="false"/> <date value="2022-02-16T00:00:00-00:00"/> <publisher value="National Cancer Institute (NCI) Enterprise Vocabulary Services (EVS)"/> <contact> <name value="US Department of Veterans Affairs; John Kilbourne, MD"/> <telecom> <system value="url"/> <value value="https://www.va.gov/"/> </telecom> <telecom> <system value="email"/> <value value="medrt@jpsys.com"/> </telecom> <telecom> <system value="email"/> <value value="John.Kilbourne@va.gov"/> </telecom> </contact> <description value="Medication Reference Terminology (MED-RT) is the evolutionary successor to the Veterans Health Administration National Drug File – Reference Terminology (VHA NDF-RT). Both are formal ontology representations of medication terminology, pharmacologic classifications, and asserted authoritative relationships between them. The MED-RT code system includes relationships between MED-RT concepts and concepts in external code systems, as well as relationships between concepts only in the external code systems. The external code systems that MED-RT references include RxNorm, MeSH, and SNOMED CT US Edition. MED-RT can be downloaded from https://evs.nci.nih.gov/ftp1/MED-RT/ For more information, please see https://ncit.nci.nih.gov/ncitbrowser/pages/vocabulary.jsf?dictionary=MED-RT"/> <copyright value="MED-RT has no copyright acknowledgement required. However, users must adhere to the UMLS license."/> <caseSensitive value="true"/> <content value="not-present"/> </CodeSystem>