I've seen multiple. The one I like is 'pinks and blues' where you're given two of each - a pink and a blue - and you write out why you think two dudes should get a blue (good) and a bad (pink). If you start accruing a bunch of pinks, there's a problem.

It's very simple and probably wouldn't pass muster with an HR department, but it was effective at getting rid of turds.

Can you split the votes as you want among the candidates or does each have to get at least one review? How often do you rate? Do you only rate peers, or new hires? What about superiors?

I could not find any reference to this system. As a person below said it recalls https://en.wikipedia.org/wiki/Limited_voting

It's a form of limited voting, with both approval and disapproval votes. In a unit, maybe there are 20-40 "candidates" and you are given four votes, two up and two down. This will probably identify a couple people receiving more than one vote. Limited voting has had interesting results in things like city council elections.

It sounds like it's not an automated rating system and doesn't rank people. It only identifies really good people and really bad people.