When a user shares their details with you, Yoti generates two user identifiers and provides them to your web application. One of these identifiers relates the user globally across your organisation and the second is specific to the application they are sharing with. If a user visits your web app again, the same identifier is provided, so that your system can recognise them as returning users. If you would like your application to be anonymous you will need to untick this in the Yoti Hub.