Today, when looking for safe or high-quality products, test marks awarded by neutral testing bodies act as guidelines and beacons of light in a sea awash with products. However, what exactly is behind the test marks? What do GS mark, CE marking and other marks actually stand for? And how are these marks interpreted correctly? These questions are answered by Berthold Tempel, laboratory director at TÜV Rheinland (Rhineland Technical Inspection Agency) and chairman of various playground safety standards committees.