The election for moderators is currently going on. Three new moderators will be elected.

On the election page you are allowed to rank your choices of the candidates. It is a little unclear whether you can rank 3 candidates or any number. But, irrespective of that, I'm wondering about the process for determining the winners based on these rankings.

Elsewhere on meta it has been said that each voter gets a "Single Transferable Vote." Can this be made a little more precise? Under what circumstances is my vote transferred from my 1st to 2nd place selection?

I worry that, because multiple moderators are being elected, this process may be gameable; but because I don't know the exact process I can't say for sure.