Multi-Voltage CMOS MVCMOS is a design methodology for very low power supply voltages that uses low-threshold transistors in series with the supply rails. The control voltages on the gating transistors need to be outside of the Vdd Vss range hence the name MVCMOS in order to reduce the standby current, but the resulting circuits operate at lower supply voltages and have a lower area overhead than the previously proposed Multi-Threshold CMOS MTCMOS.
Mircea R. Stan