FLORENCE, Italy -- Fans attending World Cup matches in Russia won't be left wondering about the reasons behind decisions of the video assistant referee.
After a decision is made using VAR, replays will be shown on giant screens inside the stadiums accompanied by a written explanation.
It's all part of the VAR information system that FIFA unveiled Wednesday .
FIFA will place someone in the VOR (video operations room) who will listen in to the VAR's decisions and communicate them to both TV commentators and stadium personnel operating the giant screens.
"So we will have graphics on the giant screens, we will have replays after the decision on the giant screens, and we will also inform the fans about the outcome of a VAR incident and review," said Sebastian Runge, group leader of football innovation at FIFA.
With the VAR making its tournament debut during the June 14-July 15 World Cup, FIFA is holding its final training camp this month for the 99 match officials -- 36 referees and 63 assistants -- who have been selected to go to Russia.
Thirteen VARs have been pre-selected and are being trained at Italy's Coverciano complex, and FIFA referees chief Pierluigi Collina said more VARs and VAR assistants will be chosen from the 99 match officials.
Three of the 13 VARs come from Italy's Serie A and two from Germany's Bundesliga -- elite competitions that already use video assistants.
The VAR can support the referee in four game-changing situations: goals and offenses leading up to a goal, penalty decisions and offenses leading up to a penalty, direct red card incidents and cases of mistaken identity.
Still, VARs in both Italy and Germany have received vehement criticism for long delays and bungled decisions this season.
On Monday, Mainz were awarded a penalty during half-time against a rival Freiburg side that had already left the pitch for the break -- prompting the unusual scene of a team returning from the changing room to defend a penalty.
"Yesterday we had already discussed this incident here and gave match officials and VARs clear indication about what should be done if something similar in FIFA competition -- specifically the World Cup -- happens," Collina said without providing further detail.
Collina added that the VAR should not be overused, adding that ideally it wouldn't intervene at all in a match.
"The goal of VAR is to avoid major mistakes," Collina said. "The objective is not to have clear and obvious mistakes committed on the field of play. This is the target, the goal is not to re-referee the match using technology.
"There will continue to be incidents when a final answer will not be given and there will be different opinions," Collina added.
Other information about the use of the VAR:
Moscow Control Center
FIFA will follow the Bundesliga model of a central control center for the VAR rather than using trucks outside stadiums.
"We will have all of the referees based in Moscow so there won't be any stress in terms of travel," Collina said.
For each match, Collina will select one VAR and three assistant VARs.
Training operation rooms presented to media included six monitors for the VARs and two more for technical assistants enabling the VARs to see requested replays.
There could be up to four technical assistants in the room for World Cup matches.
FIFA will install two extra cameras at matches to monitor offside decisions.
The cameras will be in addition to the 33 cameras used for broadcasters and they will be installed under stadium roofs.
Broadcasters will not have direct access to the cameras but if they are used by the VAR then broadcasters can show the video.
Runge added that three-dimensional technology -- considered the ultimate strategy for determining offside -- is not ready for real-time access yet.
VARs will only do one match per day
VARs will not officiate more than one match per day.
"It's not like watching a match on the sofa sipping coffee," Collina said.
Collina, who officiated Brazil's 2-0 win over Germany in the 2002 World Cup final, explained why the VARs will wear track suits similar to referees' on-pitch attire.
"The reason is at the end they sweat as much as someone on the field, because the tension is very high," Collina said. "They can't do two matches per day -- it's too stressful."
Comms and Hacking
The Moscow control center will be connected to match officials via a fiber optic network.
If the network fails, the backup plan includes an old-fashioned land telephone line and a telephone stationed near the fourth referee for emergency use.
"Worst-case scenario includes a backup plan on site. That's when the IBC is down -- no power, no fiber network," Runge said. "Then we have a plan in place where the fourth official would become the VAR and the fourth official would be replaced by the reserve referee.
"We have a cabin in the broadcast compound from where we send all of the feeds to the IBC anyway. That cabin can be turned into a smaller, light version of the VOR."
Hacking has also been considered.
"We are aware that there might be something but our IT department put measurements in place that will protect us from that," Runge said.
In extraordinary circumstances, FIFA will hold postmatch briefings to explain decisions in greater detail.
"If something should happen that we think should properly and accurately be explained -- and it doesn't matter if it's related to VAR or something different -- if it is a matter to explain the background of a decision, as an exception certainly we will do it," Collina said.
"But it won't be a postmatch news conference for every match, explaining every single decision taken during every single match."