What is a dcm?

I see this guy at the gym with a shirt that reads, 'DCM.' He practices some type of hybrid MMA. It's intense. I think DCM is a style of Martial Arts. I'm not sure. Maybe it's a brotherhood or a fight club of some kind.

DCM is an acronym for the Dynamic Combat Method™, or Dynamic Combat™ for short. DCM is a hard core, sophisticated reality-based fighting art created by martial arts master Richard Ryan through more than 30 years of scientific research, reality testing and personal development. Found on the Dynamic Combat site. I hope it is helpful. :)