Ahead of European Parliament elections in 2019, as well as continuous elections happening at local, regional and national level around Europe, Equinet - the European Network of Equality Bodies (in which network the Office of the Commissioner for Fundamental Rights is a member institution) has developed a Recommendation to be considered by political parties, candidates and media outlets (including social media) which focuses on the general principle of equality, prohibition of discrimination, tackling hate speech, addressing sensitive topics and promoting equal representation on electoral lists.

You can read the recommendations here:
COMBATTING DISCRIMINATION AND HATE SPEECH IN ELECTION CAMPAIGNS