This code system http://terminology.hl7.org/CodeSystem/MSH defines many codes, but they are not represented here

 <status value="active"/> <experimental value="false"/> <date value="2019-03-20T00:00:00-04:00"/> <publisher value="TBD - External Body"/> <description value="Medical Subject Headings (MeSH). Bethesda (MD): National Library of Medicine, 2004"/> <content value="not-present"/> </CodeSystem>