# description
Identifies the modes of usage of a questionnaire that should enable a particular questionnaire item.

# concept[].definition
Render the item regardless of usage mode.

# concept[].definition
Render the item only when capturing data.

# concept[].definition
Render the item only when displaying a completed form.

# concept[].definition
Render the item only when displaying a completed form and the item has been answered (or has child items that have been answered).

# concept[].definition
Render 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).