Currently there is a 220v tag, which seems to be used for both US 240V and UK 230V. I propose we create two separate tags 240v and 230v, and eliminate the 220v tag.
110 and 220 are terms more commonly used by amateurs, where as 120/240V, 240V, and 230V are the accepted industry standards.
Side note: I've already created a 120-240v tag, to represent 120/240V single split phase systems.