DIN 7161 relies heavily on two systems to establish fits, though the is the most common in modern machining because it is cheaper to drill/ream standard holes and turn custom shafts.
But in 1988, the international community struck a deal. The series (parts 1 and 2) was the future—a cleaner, globally harmonized system for general tolerances. Germany had to adapt. Instead of abruptly discarding DIN 7161, the German Institute for Standardization (DIN) issued a Beiblatt (supplement). It said: "DIN 7161 is withdrawn. For new designs, use DIN ISO 2768. However, to avoid legal chaos for existing products, here is a conversion table." din 7161 pdf