This code system http://hl7.org/fhir/medicinal-product-special-measures defines the following codes:

Code Display Definition
Post-authorisationStudies Requirement to conduct post-authorisation studies Requirement to conduct post-authorisation studies
<status value="draft"/> <experimental value="false"/> <date value="2021-01-05T10:01:24+11:00"/> <publisher value="HL7 (FHIR Project)"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> <telecom> <system value="email"/> <value value="fhir@lists.hl7.org"/> </telecom> </contact> <description value="Extra measures defined for a Medicinal Product, such as requirement to conduct post-authorisation studies."/> <caseSensitive value="true"/> <valueSet value="http://hl7.org/fhir/ValueSet/medicinal-product-special-measures"/> <content value="complete"/> <concept> <code value="Post-authorisationStudies"/> <display value="Requirement to conduct post-authorisation studies"/> <definition value="Requirement to conduct post-authorisation studies"/> </concept> </CodeSystem>