Regulation (EU) 2017/458 of the European Parliament and of the Council of 15 March 2017 amending Regulation (EU) 2016/399 as regards the reinforcement of checks against relevant databases at external borders
Extracts from the Regulation's preamble :
(2) Minimum checks based on a rapid and straightforward verification of the validity of the travel document for crossing the border are currently the rule for persons enjoying the right of free movement under Union law. The phenomenon of foreign terrorist fighters, many of whom are Union citizens, demonstrates the need to reinforce checks at external borders with regard to persons enjoying the right of free movement under Union law.
(3) The travel documents of persons enjoying the right of free movement under Union law should therefore be checked systematically, on entry into and on exit from the territory of Member States, against relevant databases for stolen, misappropriated, lost and invalidated travel documents in order to ensure that such persons do not hide their real identity.
(4) Member States are obliged to check systematically third-country nationals against all relevant databases on entry. It should be ensured that such checks are also carried out systematically on exit.
(5) Border guards should also systematically check persons enjoying the right of free movement under Union law against the Schengen Information System (SIS) and other relevant Union databases. This should be without prejudice to the consultation of national and Interpol databases.