Just to be the Colt stickler on this board, I have to point out that Commanders are only made in West Hartford, CT. Ruger will have to call its gun something else...
They refer to it on their website as "commander-style" or SR1911CMD.
Most other 1911 manufacturers follow the same name designations as Colt did originally. For example...
Government (full size) = 5"
Commander = 4"-4.25"
Officer = 3"-3.5"
Kimber uses "Pro" and "Ultra" to designate their commander and officer ones to differentiate from other manufacturers.