Supporters who want to attend Confederations Cup matches in Russia are facing a rather unusual requirement -- having to get a Fan ID. According to the rules, no fan will be able enter a stadium without the document, which resembles an accreditation. The authorities want to know a lot about people in the stands, putting their passport numbers, personal details and photographs in a huge database.

One aspect of the project could become a positive: Supporters don't need to get a visa if they have a Fan ID. Fans from all over the world can enter Russia 10 days prior to the opening game and leave the country 10 days after the final without having to undergo the long bureaucratic process of acquiring a visa. There is a problem, though. As convenient as not getting a visa may seem, many fans were unaware of such an option, and conversely, having a visa doesn't mean they will be free of the obligation to get a Fan ID.

Eric and Nadia, two Mexican fans ESPN FC met at the ticketing center in Moscow, were surprised to find out about the new requirement. "We didn't know anything about it before arriving to Moscow. That is unfortunate, because getting the Russian visa was an extremely tiresome process. We had to send over confirmations from every hotel we are planning to stay at, and that was simply exhausting," Eric said.

Once in Russia, they were disappointed to have to make numerous trips to complete the registration. There are only three ticketing centers. One of them is suitably placed at the Domodedovo airport, but the other two are quite a challenge to reach. In addition, there are three Fan ID centers in totally different places -- one at Spartak's Otkrytie Arena, which hosts the tournament but is located far from the city center. Curiously, it appears on the list published on the website, but is absent from the booklet that is distributed among fans. Eric and Nadia were unaware of it, and somewhat relieved when informed because the additional centers are even more difficult to reach.

Jorge, a Chilean fan who made the long trip to the Fan ID center at Otkrytie Arena, was angry about the situation. "I don't understand why they need to issue those IDs. And why can't they provide them at ticketing centers at the very least?" he wondered.

The answer seems to be that the tickets are distributed by FIFA, but the Fan ID project is a Russian initiative that has nothing to do with FIFA. Football's governing body states that specifically on its website: "FIFA does not assume any liability or responsibility in respect of the application, issuance and use of such identification documents [Fan ID]".

Fans who knew about the Fan IDs and who planned their trip in advance might feel more comfortable with the situation. Filling the form on the Internet might have been a little problematic, because fans are required to download a photograph that is taken according to very strict rules (especially a completely white background), but they could have ordered the Fan IDs to be mailed to them and didn't have to apply for a visa. Free transportation on matchdays for Fan ID holders is also a significant bonus, but again, it is hard to take advantage of this without knowing about it in advance.

For those who made the decision to go to the Confederation Cup spontaneously, or who didn't know which games they would go to beforehand, there could be a significant hassle. Applying for Fan IDs is only possible after purchasing tickets, and therefore they couldn't start the process in advance. After entering Russia, fans must take time and go to two faraway places in order to get all the documents.

The biggest problem, though, seems to be awareness. Even though the Fan ID requirement is stated on the FIFA website, it is easy to miss it, and many fans don't purchase their tickets themselves anyway. Some might be advised to get a Fan ID at a ticketing center, but it is far from certain that all fans will know the rule. It would be natural for fans to assume that purchasing a ticket is enough, because that has always been the case.

"The authorities tried the Fan ID idea at the Winter Olympics in Sochi [in Russia] and they seem to have liked it," Sport Express journalist Filipp Papenkov told ESPN FC. "However, Sochi was a very small venue, while the Confederations Cup takes place in four cities, and the World Cup is going to be a huge affair."

That is indeed a matter for concern. It is clearly stated on the official website that Russia intends to continue the project next summer at the World Cup: "A Fan ID issued for the FIFA Confederations Cup 2017 will not be valid for the 2018 FIFA World Cup. The holders of tickets to the matches of the 2018 FIFA World Cup will need to obtain another Fan ID. More detailed information about obtaining a Fan ID for the 2018 FIFA World Cup will be available at the official website after the FIFA Confederations Cup 2017."

"There could be a lot of fans all over Russia without the required Fan IDs during the World Cup. If they are denied from entering stadiums despite buying the tickets, the situation might go out of control," Papenkov warned.

It is easy to imagine the anger of supporters who made the long trip and invested considerable sums of money only to be left empty-handed because they didn't apply for a document they were not aware of.

"It is also unclear whether the authorities can actually handle issuing hundreds of thousands of Fan IDs in a very short period of time. We don't have a lot of visitors for the Confederations Cup -- just a few Portuguese, Mexican and Chilean supporters. But the situation will be very different in 2018," Papenkov said.

And that could possibly be a major problem during the World Cup.