The language describing itemControl's 'check-box' and 'radio-button' should be revised to make it clear that one can also apply them to items of type "boolean", with the purpose being to guide the form filler as to what UI control to use for the Boolean.

There was also a request on the SDC workgroup call to possibly revise the text of https://build.fhir.org/questionnaire.html#booleans for this issue.