This code system https://fhir.ehealth-systems.at/kiola/boolean defines the following codes:

CodeDisplay
true True
false False
 <status value="active"/> <date value="2024-04-27T13:32:49+00:00"/> <contact> <name value="AIT Austrian Institute of Technology"/> <telecom> <system value="email"/> <value value="mailto:office@ait.ac.at"/> </telecom> </contact> <content value="complete"/> <count value="2"/> <concept> <code value="true"/> <display value="True"/> </concept> <concept> <code value="false"/> <display value="False"/> </concept> </CodeSystem>