DC is datacenter.

"Our VPS servers are housed in multi homed facilities in Detroit, Pheonix, San Diego and Seattle. The bandwidth (95th % Aggregated Tier 1 Bandwidth) is made up of At&t, Level3, Spectrum, Comcast, XO, NTT, Savvis, SIX, Global, Qwest."

http://rockstarvps.com/network.php