Thematic track “Once Only Principle (OOP)” Guus Bronkhorst: Once only, only once Panel discussion: "Once only principle and data protection: Foes or friends?" Gilles Feith: OOP and reuse of data in Luxembourg Peter Kustor: Data protection as an integral part of OOP implementations: The Austrian approach Mechthild Rohen: Horizon 2020 WP 2016-17: “Once Only Large Scale Pilot”