It makes sense that the world would like to keep a detailed account of who has nuclear weapons and how many.

After all, studies have found that it would only take 100 (give or take) warheads to cause the onset of a nuclear winter, and the world currently has about 12,500 of them.

If you check it out, though, you might wonder why “Jeff” has as many nukes as North Korea.

One of many questions that would pop up, I’m sure.

who the hell is jeff pic.twitter.com/UlKVBbBLgw

— Bob Vulfov (@bobvulfov) December 31, 2016

There are nine countries in possession of nuclear weapons currently: Russia, USA, China, the UK, France, Pakistan, Israel, North Korea, and India.

And then there is Jeff.

Contrary to popular guesses (that it’s Jeff Bezos, or maybe Jeff Goldblum), it’s just an acronym for Joint Evaluated Fission and Fusion Project.

JEFF is an international collaboration to create a library of nuclear data, and doesn’t hold actual nuclear weapons.

So now you know!