A DIN regulator can be attached only to a DIN valve, which is incompatible with standard Yoke regulators and valves. The best way to check if your valve requires a DIN regulator is to check where the two connect - if they must be screwed together, there is a good chance you have a DIN valve. If a metal brace has to go over the tank valve, and the brace screwed down to clamp the first stage, then you have a Yoke valve. DIN valve/regulator connections are more streamlined than Yoke connections, requiring less outside hardware to attach. A DIN valve and regulator can also handle higher pressures when configured correctly.
A DIN to YOKE adapter is perfect for keeping your DIN regulator when only yoke tanks are available.