This code system http://terminology.hl7.org/CodeSystem/question-max-occurs defines the following codes:

Code Display Definition
* Repeating Element can repeat an unlimited number of times.
<status value="draft"/> <experimental value="false"/> <date value="2020-08-20T17:41:31+10:00"/> <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="Flags an element as having unlimited repetitions."/> <caseSensitive value="true"/> <valueSet value="http://hl7.org/fhir/ValueSet/question-max-occurs"/> <content value="complete"/> <concept> <code value="*"/> <display value="Repeating"/> <definition value="Element can repeat an unlimited number of times."/> </concept> </CodeSystem>