I mean, we are talking about it now. It is an interesting topic. It's just very poorly written. Maybe this attention will help fix that?
From what I've been able to understand, this just means that you can buy a radio from vendor A, and I can buy one from vendor B. As long as they both claim to be part of the DMR standard, then both radios should be able to communicate with each other. Since it's digital, I'm assuming the standard describes the word length and other various aspects so that anyone can decode/encode the proper AD/DA.
But man, why couldn't they just say that?
Fair enough and it sounds like it has. Maybe in future the YC title can be prefixed with something like 'Call to assist: ', for the benefit of those less inclined to edit such articles.
DMR is a mobile radio standard. Think of a private network of walkie-talkies, vehicle-mounted and desk mounted radios connecting professional users. Let me know if I can find a better resource for you.