The aim of these guidelines from the Article 29 Working Party is to clarify the relevant provisions in the GDPR in order to help organizations comply with the GDPR's requirement for certain controllers and processors to designate a DPO, but also to assist DPOs in their role. The guidelines also provide best practice recommendations, building on the experience gained in some EU member states. The WP29 will monitor the implementation of these guidelines and may complement them with further details as appropriate. (Issued December, 2016, and revised April 5, 2017)
The WP29 published in December 2016 a complementary FAQ on DPOs here.