Yes. which means you need to learn them from an instructor, or just by going diving with DIR divers, the same way you learnt everything else you do as a diver. DIR is no different, sorry. I know you are digging, but the only hole you are digging is for yourself. There is no big conspiracy - it's really just one way of going diving, people can take it or leave it. If you don't want to be a rebreather diver, you don't have to buy a rebreather. DIR diving is not mandatory.