Here's what you should know about the "OK" hand sign by now: In early 2017, a bunch of trolls on 4chan thought it would be funny to trick the media into claiming the "OK" hand sign - thumb and forefinger making a ring, other fingers pointed out - is a secret Nazi symbol. Prominent figures on the pro-Trump Internet were into it for the same reason's they're into a lot of things: to "trigger" liberals. The trolling worked. Then actual white nationalists started using the symbol, too.

The "OK" hand sign now lives in a purgatory of meaning, along with other memes that have been at least partially radicalized because online racists thought it would be funny to radicalize them. Pepe the Frog lives there too, as does "Kek," originally an inside joke from World of Warcraft that, by way of 4chan, now appears on banners stylized to look like Nazi flags at white nationalist rallies. We're in purgatory, too, paralyzed by the desire to react strongly to expressions of racist extremism while also acknowledging that the "OK" hand sign simultaneously does and does not signify those beliefs.

It's a trap designed to ensnare well-meaning people by hacking our tools for understanding each other. And it works every time.

The Anti-Defamation League officially included the 'okay' hand sign it in its "Hate on Display" database in 2019. Here's what you need to know about the evolution of the symbol. (The Washington Post)

The circumstances of the latest "OK" sign blowup made the ambiguity all the more unsettling, since it involved U.S. military institutions. At Saturday's Army-Navy game, two U.S. Military Academy cadets and a Naval Academy midshipman flashed upside-down "OK" signs on camera behind an ESPN reporter.

The military academies are now investigating the intent of the students. The hand gestures they did resemble the one that the Anti-Defamation League recently added - with some ambiguity-related caveats - to their database of hate symbols. It also resembles the hand gesture associated with the "circle game," a made-you-look prank that predates the "OK" hand sign's transformation into a sometimes hate symbol.

Both the circle-game and white-power versions of the "OK" hand sign require your attention to work, and you lose as soon as you give it to them.

The circle game's goal is to trick someone into looking at your hand while you're making a circle with index and thumb. If you look, you get punched in the arm. It's an old game, popularized by a 2000 episode of "Malcolm in the Middle." But it's also a running meme on YouTube and TikTok.

The racist version comes with its own punch. When spotted, it tends to cause unstoppable cycle of media amplification that inadvertently helps to draw mainstream attention to extremist views.

When the "OK" sign goes viral, the silos of outrage and claims that the perpetrators were "just trolling" spread way ahead of the context. During the confirmation hearings for Justice Brett Kavanaugh, Republican operative Zina Bash was seen resting her hand in an "OK"-like position while visible on camera. When she used the "OK" sign again, days later, #Resistance Twitter accused Bash of signaling to white supremacists. The likely truth is much more mundane: Bash was signaling to a colleague that her request for water had been fulfilled. Nevertheless, it caused a week of agita and speculation.

There have been other examples. An "OK" sign appeared behind a black reporter at a Cubs game. A Coast Guard member was removed from Hurricane Florence relief efforts after he flashed the "OK" sign during a televised media briefing.

Brenton Tarrant, the Australian white supremacist who is accused of killing 51 people in New Zealand, flashed an "OK" symbol during a court appearance. His hand was placed down low and upside down, like the circle-game version. The mass shooting, the manifesto, the live-streaming of the Christchurch massacre were steeped in edgy meme culture and engineered to go viral to serve the gunman's extremist views.

People seem to want the "OK" hand sign to work like a secret decoder ring, identifying white supremacy for those who are otherwise unable to see it. But instead, the "OK" hand sign works more like a sleight of hand.

To understand how, you have to understand Poe's Law.

In 2005, a message board user writing under the name Nathan Poe described how hard it is to figure out the intent of someone else online. At the time, he was talking about creationists. Poe wrote: "Without a winking smiley or other blatant display of humor, it is utterly impossible to parody a Creationist in such a way that someone won't mistake for the genuine article."

Poe's law became a reference point for any situation on the Internet where you can't truly tell someone's motives or intentions, It explains how "just trolling" has become a powerful cover for unironic expressions of racism or extremist views online, said Ryan Milner, an associate professor at the College of Charleston who studies meme culture, in a 2017 interview with The Washington Post.

It can be tough to understand the motivation behind the "OK" hand sign just by looking at it. And so two things can easily happen: People get wrongly accused of promoting white supremacy because of a hand gesture they made and actual uses by attention-seeking extremists can be explained away as misinterpretations of something more innocuous.

"People embrace irony, run to it, and use it as a shield to dip into a more objectionable idea," Milner said in 2017.

Even the Anti-Defamation League's database entry for the "OK" hand symbol notes the trickiness here, noting that the "overwhelming usage of the "OK" hand gesture today is still its traditional purpose". Even as there real white supremacists use it to get our attention, other people will keep flashing "OK," for unrelated reasons, on TikTok and at school and at sporting events.

There is no way to "win" the circle game. All you can do is avoid looking for as long as you can. The game that keeps the "OK" hand sign in the news is even harder: getting trolled is harder to avoid when actual white supremacy has crept out of the shadows, and especially when its adherents are targeting you. You cant' stop seeing it, and everybody keeps punching each other in the arm.

This article was written by Abby Ohlheiser, a reporter for The Washington Post.