- Create an event, add an attendee - Click on the stat button 'Mail Attendees' The domain is shown as 'Event', '?', [id]. This is because the domain selector widget doesn't support the `in` operator. Supporting it is not trivial, since ultimately `field_utils` cannot parse a list of ids for a Many2one. It's less intrusive to change the domain, since a standard use of the method will simply contain a single id. opw-1878322