“…Even though they are soft law by nature, they gain quasi-legal relevance through certain procedural requirements (Schemmel, 2016). This character ambiguity makes them one of the most discussed phenomena in the literature on the ESA (Busuioc, 2013;Chiti, 2013;Fahey, 2012;Moloney, 2011a;van Rijsbergen, 2014;Wörner, 2017). This article, however, will discuss the instruments that are most relevant to the principles of European Union law and have proven to be pacemakers for the European integration: ESA' powers on Level 2 and 4, i.e.…”