Handing over a captionset is useful when translators are sharing a project, or when a project needs to be handed over to a validator for checking. The 'Handover' button is only visible when more than one linguist has been assigned to a captionset.
Clicking the 'Handover' button shows a dropdown menu, with a list of users assigned to this particular captionset. Choose the user you want to hand the captionset over to, and click the button. The recipient will receive an automated email, as well as the producer who's managing the project.