It is possible that a user, under very specific conditions, may have to transfer the ownership of an event that he is processing (for example if he is not the best placed user to process this event, or when he finishes his shift). It is then possible for a user to select one or more events and assign them to another user. It is also possible to unassign himself from these events and send them back to the first tab. In both cases, the progress that has been made on these events won't be lost.