Apparently here's what Garrett means by RKG:
Garrett describes 'the right kind of guy' and says ego is part of it
March 26, 2012
Cowboys coach Jason Garrett said he wants players with ego. But the right kind of ego.
“Ego in the context of what we’re trying to accomplish as a team,” he said Saturday at a high school football camp at Cowboys Stadium. He was asked by reporters to describe the kind of player he is looking for in free agency.
“We’re looking for the right kind of guy,” he said. “The right kind of guy, to us, is someone who loves to play football, who is very passionate about it, willing to work hard at it, willing to be part of a team, willing to be part of something that is maybe greater than himself.
“We want a guy who has an ego. Egos are important. But ego in the context of what we’re trying to accomplish as a team. Guys who are willing to work, are great teammates – there’s always going to be a place for those guys.”
-- Carlos Mendez
Read more here:
Cowboys Corner: Garrett describes 'the right kind of guy' and says ego is part of it
This definition doesn't necessarily preclude guys like Josh Brent, Michael Irvin, Dez, Hamilton, Spiller or even Rafael Septien.
RKG doesn't mean "high moral character."
Certainly people can argue that they'd like for Garrett to enforce a higher "moral character" threshold, but Garrett's "RKG" term refers to something different from that.