The (single) turbocharged version of the VQ displaces 30 deciliters (3.0 liters) and is logically called the VQ30DET.
For example, the SR20VE engine has dual overhead camshafts, but the variable valve lift design of the camshafts takes precedence in the naming scheme even though the "V" feature designation doesn't necessarily describe a DOHC arrangement.
Many standard DOHC Nissan engines featured Variable Valve Timing, such as the VG30DETT, and as such do not use the "V" designation.
Lastly, there are engines built specifically as power generators for electric motors, designated with the lowercase "e".
The feature letters describe it as an engine with dual overhead camshafts, direct cylinder fuel injection with variable valve timing (bear in mind that the "V" designation is not used here, as that is used for variable valve lift) and is used as a power generator for electric motors.