TAMPA, Fla. — Amid the “Trump 2020” placards, the “Women for Trump” signs and the “CNN SUCKS” T-shirts, the most inscrutable message that came out of Donald Trump’s Tampa rally on Tuesday evening was a letter.

Q.

People wore T-shirts with the letter emblazoned on the front. Others carried signs containing the letter: “Q WWG1WGA Trump 2020 Keep America Great! MSM is the enemy.” Another held a dog-eared and slightly crumpled piece of paper in the air. It said, simply, “We are Q.”

Q who?

The entire, loose movement has been called everything from “a deranged conspiracy cult” (The Washington Post) to a grassroots movement “about the covert battles being waged between the deep state and President Trump” (according to Tyler, a guy at the Tampa rally who held a metal coin emblazoned with the letter and showed it to WPLG, a TV station from Miami).

Here’s a look at the trend that’s sweeping certain dark corners of the internet:

Who is Q?

In late October 2017, an anonymous user posted on 4chan, a shadowy site known for, among other things, cruel hoaxes and political extremism. Under the title “The Calm Before the Storm,” the poster claimed to have a high-level government security clearance — Q clearance to be exact — and referred to Donald Trump, Hillary Clinton, George Soros, political parties and former President Barack Obama.

Q gives readers “breadcrumbs” so they can ferret out details on their own. There’s other lingo as well. Bakers are amateur sleuths who follow the crumbs. Anyone who tries to debunk Q is “a clown.” (This includes CIA agents, shadowy operatives and most likely reporters, although there’s separate terminology for them).

Like Tyler, the man at the Tuesday rally in Tampa, many believe the mainstream media is lying to them.

Other 4chan users have pointed out that “Q” uses the plural “we.”

Keep in mind, users can, and often do, post anonymously on 4chan.

Everybody on the internet talks about Trump, Clinton, Obama and Soros. What makes Q different?

Many on 4chan seemed to enjoy discussing the cryptic posts and the clues, and Q spread like wildfire. Terminology was born. Inside jokes and theories blossomed. Q subreddits swelled to 30,000 followers. Q’s Twitter account has 80,000 followers.

A YouTube video posted by “prayingmedic” on July 28, titled, “Something Big is About to Drop,” has 275,000 views. It is an hour and eight minutes long.

It is unclear if anything actually dropped.

Joseph Uscinski, a University of Miami professor who co-authored the book “American Conspiracy Theories” said Q “is just hitting the right audience at the right time given the right circumstance.”

Q’s topics appeal to many who already are inclined to believe conspiracy theories, Uscinski said. Those conspiracy-minded folks have always been around in the country.

“There is no way to know if it’s an embedded deep state operative or if it’s a prankster,” he added.

What does this have to do with Roseanne Barr?

The actress has tweeted about Q and retweeted posts from the “QAnon” account. In November 2017, she tweeted “Who is Q?” and reportedly asked Q to direct message her. In May, Barr posted a racist tweet about former White House adviser Valerie Jarrett, who figures in some QAnon conspiracy theories. In response, ABC cancelled her hit TV show.

What does Q believe?

Uscinski, who has studied Q over the last month, says the user’s posts are often about the “deep state” battling Trump, using bureaucratic inertia. Which isn’t that farfetched, he said, given that many in federal government didn’t likely vote for Trump.

Q and the QAnon supporters refer to “The Storm” often, which is a reference to an October 2017 meeting between Trump and military leaders during which Trump said “the calm before the storm.”

But then, things get nutty.

Q has posted that Special Counsel Robert Mueller isn’t investigating Trump at all — he’s really investigating Clinton, John Podesta and Obama. Other theories involve familiar players in conspiracy theories such as the Freemasons and the Illuminati, while others mention The Titanic, pedophile rings in Hollywood, and the possibility that former Clinton aide Huma Abedin wears an ankle monitor. Filmmaker Francis Ford Coppola, the Rothschild family and Satan also make appearances in discussions.

Sometimes the posts are cryptic, throwing the bakers into a frenzy of riddle solving, such as:

—27-1_yes_USA94-2

—27-1_yes_USA58-A

—27-1_yes_USA04

—Conf_BECZ_y056-(3)_y

The_Castle_Runs_RED_yes

Godspeed.

How long do experts think Q will continue posting?

Said Uscinski: “Very few conspiracies have the staying power of a JFK.”