The Article 29 Working Party published two Guidelines related to GDPR:
Guidelines on Personal data breach notification under Regulation 2016/679, wp250
Guidelines on automated individual decision-making and profiling for the purposes of Regulation 2016/679, wp251
The Guidelines are open for comments until November, 28, 2017. Comments should be sent to JUST-ARTICLE29WP-SEC@ec.europa.eu and email@example.com.