<status value="draft"/> <experimental value="true"/> <publisher value="HL7 International / FHIR Infrastructure"/> <contact> <telecom> <system value="url"/> <value value="http://www.hl7.org/Special/committees/fiwg"/> </telecom> </contact> <description value="Search by url for a participation agreement, which is stored as an extension referencing a DocumentReference"/> <code value="part-agree"/> <base value="Patient"/> <type value="reference"/> <expression value="Patient.extension('http://example.org/fhir/StructureDefinition/participation-agreement').value"/> <processingMode value="normal"/> <target value="DocumentReference"/> </SearchParameter>