Nitrox >40% din is officialy different but can be changed very easy into the normal DIN connector.
The official european norm for O2 clean is M26/2 but this standard is not really beeing kept as it limits the use of your regulators.
That's exactly right. I have a pair of Scubapro Mk2+/R195 Nitrox regulators I purchased from Europe and they are fitted with the M26 male so they will not work with DIN 300 or DIN 232 BAR cylinders. You can change out the M26 to either DIN, however I opted to go for an M26 female to DIN 300 Male adapter rather than swap out the entire DIN connector.