The NFL combine is an event to see and be seen.

Walk the corridors of the Indiana Convention Center, or the nearby hotel lobbies and bars, and there's a parade of coaches, executives, scouts, draft prospects, agents and media. But amid the frenzy are hiding places, where important things happen.

As the saying goes, the combine you don't see is more interesting than the one you do.

It makes the combine a perfect spot for the NCAA to host college football's biggest stars. Tua Tagovailoa was in Indianapolis this past weekend, along with five of his Alabama teammates. So was Georgia quarterback Jake Fromm, joined by his blind-side protector, tackle Andrew Thomas. LSU All-America safety Grant Delpit ditched Mardi Gras to be there. Jonathan Taylor, college football's leading rusher in 2018, left frigid Wisconsin for slightly less-frigid Indy. The national champs were represented, as Clemson running back Travis Etienne and linebacker Isaiah Simmons both made the trip.

Did anyone spot Tua, Fromm, Taylor, Delpit and Etienne around town? Probably not. Did they know the NCAA brings in a group of top college players to this event every year? It's unlikely.

It's also by design. The NCAA's Elite Football Symposium, launched in 2017, provides high-profile college players information they need for the NFL transition, while shielding them from the combine spotlight. Held at NCAA headquarters, located several hundred yards from the hub of combine activity, the event puts players through three days of meetings about agents, money management, NFL contracts, scouting, social media and branding, and other topics.

"They tried to keep us away from the general public overall," Alabama linebacker Dylan Moses said. "We couldn't stay out too late. They told us, straight up, that it's a business trip. You're not here to have fun. You're here to get information about your future."

Players are advised to not venture far from their hotel. They are asked to stay off social media, and to not wear team-issued gear when attending combine workouts at Lucas Oil Stadium. Most didn't even visit their ex-teammates participating in the combine.

"Being in Indianapolis, there were so many agents around," Stanford offensive lineman Walker Little said. "They thought it would be in our best interests to not go walking around the city. We still would go eat and stuff, but it was better to keep us away from agents trying to talk to us."

Aiming to better inform high-level college athletes about the transition to pro ball, NCAA staffers Nicole Jameson and Chris Howard helped launch elite athlete symposiums for basketball and football in 2016 and 2017, respectively.

The symposiums are invitation-only. In football, NCAA staff research players entering their third or fourth seasons who are projected as top draft selections the following year. The NCAA consults with independent draft experts to add names, if necessary. About 30 spots are available for athletes at each symposium.

UCLA's Josh Rosen and Alabama's Minkah Fitzpatrick were in the initial group of 16 players from 12 schools in 2017. Last year's symposium featured Houston's Ed Oliver, Michigan's Rashan Gary, Clemson's Dexter Lawrence, LSU's Greedy Williams and Devin White, and others who returned last week for the actual combine.

ESPN.com confirmed 25 participants from 13 schools at this year's symposium. Notables include Alabama wide receiver Jerry Jeudy, Auburn defensive lineman Derrick Brown and Boston College running back AJ Dillon.

Because of who attends the symposium and where it's held, the NCAA tightly guards information. The NCAA didn't provide a list of 2019 participants, either before or after the symposium (ESPN.com confirmed attendees through their schools). The symposium is closed to media, and the NCAA declined to make staff available for comment but provided ESPN background after receiving several questions.

Although some players know about the program from teammates who participated, others have little knowledge. "I had no clue what it was or what it was about," said Michigan quarterback Shea Patterson, who attended the 2018 symposium.

"They try to keep it pretty quiet," Delpit said. "They know a lot of agents and stuff are out there, so they just keep it on the low. They don't want people bombarding us. They don't want a lot of extra attention."

While the NCAA tries to keep agents away, the symposium dives deep into agents and money. Players learned about the process of selecting agents and financial advisers, agent fees and recruiting tactics.

"They were definitely saying we need to watch out for certain things when approaching agents," Moses said. "They also said we don't necessarily need them. They gave us certain cues to watch for."

Said Taylor: "Say, you like comics. [Agents] use that as a way to initially connect with you. It's kind of like the recruiting process. Everyone wants you."

Players weren't advised against hiring agents but heard the pros and pitfalls. They learned about NFL players who lost significant income because of poor representation.

Wisconsin running back Jonathan Taylor got a crash course in paycheck taxes. AP Photo/Darron Cummings

NFLPA officials attend the symposium and explain how professional contracts are structured, the challenges to earn a second contract, and how their paychecks break down.

"One thing I didn't know about taxes is it varies," Taylor said. "If you play in a different state, you get taxes taken out of that game check, based on the taxes in that state. You're going to be filing taxes to a lot of different places."

Speakers have included former NFL players and executives, including Ray Farmer, a former player and Cleveland Browns general manager. Players also have heard from former NFL employees in scouting, operations and security.

Delpit's favorite presentation came from Carrie Cecil, a social media and reputation management expert who told players to "scrub their Twitter" and other social platforms. She highlighted social media crises for recent draft prospects like Josh Allen and Laremy Tunsil, and the depth to which NFL teams mine prospects' social media content.

"That's what represents you," Simmons said. "They can look at anything. It's not just you; it's your friends. [The presentation] went more in-depth and went more blunt."

Players had mock interviews, like the real ones their ex-teammates were doing. They watched an hour of combine testing Saturday. They did hypotheticals based on draft selection, and how to maintain their college eligibility until they make the jump.

Most of the participants are rising juniors who will have NFL decisions after the 2019 season.

"I definitely feel more informed," Little said. "Whenever that process comes, I'll feel more confident about my ability to make decisions."

Colorado wide receiver Laviska Shenault was recognized only twice last weekend, both at the airport. But he and the others left Indianapolis with pages of notes and a better perspective on what happens when they return.

"Everybody's got a chance to make it to the NFL, but what about when you're in the NFL?" Shenault said. "You want to make sure you have goals, being in the league more than three or four years, the average. I want to make sure I'm in there as much as possible, and I want to make sure things outside of football help me toward football."