Ordering correct spoke nipple size I've got some spoke nipples on a rear wheel which are stripped, and I'd like to replace them.

I've measured the thickness of the spokes and they have a diameter of 2mm, which correspond to 14-gauge from what I've gathered on the web. The length of the nipples is 12mm. 

I ordered some DT swiss spoke nipples, which were marked as 14G 12mm, but when I received them it was written 2mm x 12mm on the box, where the 2mm isn't the thread diameter of the spoke onto which the nipples thread, but the diameter of the flat faces used to tighten them. Obviously, they didn't fit onto the 14G spokes.

What is the standard way of giving the size of spoke nipples, does 14G mean they thread onto a 2mm spoke or is it the size of the spoke tool needed to tighten them?

Thanks for any advice!
14G and 2mm are synonymous concerning the spoke thread. It should just fit.
The flats should have a distance of 3.23mm.

https://en.m.wikipedia.org/wiki/Spoke_wrench