The CALDAV
schedule-send-reply privilege controls the sending of scheduling messages by "Attendees".
Users granted the DAV:bind privilege on a calendar collection, or the DAV:write privilege on scheduling object resources, will also need the CALDAV:schedule-send-reply privilege granted on the scheduling Outbox collection of the owner of the calendar collection or scheduling object resource in order to be allowed to create, modify, or delete scheduling object resources in a way that will trigger the CalDAV server to deliver scheduling message replies to the "Organizer".