Most of the CA's I've flown with have been DECs, all have been ExpressJet or people who left flying and came back with only one exception from Mesa. It will be interesting to see how the company reacts to this, if it does.

D2T is a standby priority code that puts you above D2 (normal commuter) because you are a "through" passenger, on the list for the flight as a connection rather than the first/only leg.