Determines whether the calendar object resources in a calendar collection will affect the owner's busy time information.
This property MAY be protected and SHOULD NOT be returned by a PROPFIND DAV:allprop request (as defined in Section 14.2 of [RFC4918]).
COPY/MOVE behavior: This property value SHOULD be kept during a MOVE operation, and SHOULD be copied and preserved in a COPY.
Description: This property SHOULD be defined on all calendar collections. If present, it contains one of two XML elements that indicate whether the calendar object resources in the calendar collection ought to contribute to the owner's busy time. When the CALDAV:opaque element is used, all calendar object resources in the corresponding calendar collection MUST contribute to busy time, assuming that access privileges and other iCalendar properties allow it to. When the CALDAV:transparent XML element is used, the calendar object resources in the corresponding calendar collection MUST NOT contribute to busy time.
If this property is not present on a calendar collection, then the default value CALDAV:opaque MUST be assumed.