This code system http://hl7.org/fhir/questionnaire-usage-mode defines the following codes:

CodeDisplayDefinition
capture-displayCapture & DisplayRender the item regardless of usage mode
captureCapture OnlyRender the item only when capturing data
displayDisplay OnlyRender the item only when displaying a completed form
display-non-emptyDisplay when AnsweredRender the item only when displaying a completed form and the item has been answered (or has child items that have been answered)
capture-display-non-emptyCapture or, if answered, DisplayRender the item when capturing data or when displaying a completed form and the item has been answered (or has child items that have been answered)