The intrigue around Red Bull getting caught trying to interfere with Lando Norris's grid tape marker at Austin has added a bit of curious soap opera to the Formula 1 title battle.
What started out as a fine being handed out to Red Bull for one of its staff members ignoring the instructions of officials and returning to the grid has developed into a wider story.
There is no suggestion either squad has broken the rules with the tape - as McLaren is allowed to put it on the pitwall and Red Bull is allowed to pull it off again.
But it does bring into play questions of sportsmanship and what place that has in an intense F1 title battle.
So what is the grid marker tape all about, what would Red Bull have to gain by tampering with it, and what implications could this have going forward?
Why Norris uses tape
As The Race recently reported, Norris is one of a few drivers who uses tape on the grid to help with his car positioning.
While F1 grid boxes are 2.7 metres wide, the lack of visibility that drivers have in the cockpit can make getting into the perfect spot quite hard.
Rules are clear that a car will be deemed to have committed an offence if "any part of the contact patch of its front tyres [are] outside of the lines [front and sides] at the time of the start signal".
The FIA paints a yellow guide line towards the front of the grid box, which stretches out across the track and is supposed to help drivers judge where their front wheels need to be.
But with a low seating position, the halo, car bodywork plus front wheel covers, it is still incredibly difficult for drivers to hit the perfect spot where they are not too far forward but not so far back that they lose ground to rivals.
To help position himself better, Norris has a regular procedure on the grid that is co-ordinated with his race engineer Will Joseph.
As the McLaren driver pulls up onto the grid and has his car placed in the perfect spot by mechanics, Joseph will be positioned by the nearest wall (either to the left or right of the grid spot) and have in his hands a piece of silver tape.
With a clear line of sight between them, Norris will get the tape positioned in a location that will be in alignment with a fixed point on his car.
It means that when he comes around again at the end of the formation lap, he will be able to line up his car with the tape - and be sure that he is in as good a spot as he can be for the race start.
The use of tape like this on walls is well known in touring car racing.
Lewis Hamilton is another driver who makes use of tape for positioning, but he fixes it onto a point on his sidepod that lines up with the yellow grid box line.
Why would Red Bull interfere?
The benefits of Red Bull interfering with the tape are obvious.
If Norris comes around after the formation lap and finds that the tape has been removed - or even worse, relocated to a different position - then that could easily disrupt his start.
At best it could mean he has to be cautious so he starts too far back. At worse, he goes too far forward and picks up a grid penalty.
The Race has learned that Sunday's United States Grand Prix was not the first time that Red Bull has tried to interfere with Norris's tape - but it is the first time it has been properly caught doing it.
Sources suggest that Red Bull's behaviour of targeting Norris's tape is something quite new, and has only begun at recent races rather than having been something it got involved in earlier on in the campaign.
McLaren has become aware of Red Bull's antics and it is understood that, for Austin, it changed the way that it fixed it to the wall - to make it much more difficult to remove.
This may have played a part in the Red Bull mechanic fumbling in their efforts to interfere with the tape, and why they had to perhaps go back for a second attempt and got caught ignoring marshals' instructions.
What it means for the title battle
The games being played between Red Bull and McLaren are not something that the FIA is likely to get involved in.
There is not a regulatory element at the heart of tape being used as a reference point and the matter only came up at Austin because Red Bull breached the rules in terms of a mechanic returning to the grid.
However, the situation does raise the question of 'sportsmanship' and whether this is a bit of harmless fun or goes a bit too far.
There are plenty of areas in F1 where teams agree to play it fair even if the regulations do not demand they do so.
Pitlane behaviour is one, as there is an unwritten rule between teams that they do not leave their wheel guns spread out in their pitbox, or have team members stand in the way, to try to make life difficult for the teams next to them as they arrive or leave at their tyre changes.
There is also understood to be some form of gentleman's agreement that spy shots will not be taken when cars are in parc ferme after qualifying or the race - as that would open a Pandora's box of cheekiness.
The issue of the tape falls into an area not defined by the rules, but it does beg the question about where the line gets drawn between interfering with a grid reference marker and messing about with other team's equipment.
Would interfering with a drivers' helmet on the grid be allowed? What about hiding his gloves? Would turning off a rival team's tyre blanket heaters before the race be OK? What about blocking radio transmissions for a competitor?
The FIA's International Sporting Code does have a clause where sportsmanship is referenced.
Article 12.2.1.m states it is an offence for there to be: "Any infringement of the principles of fairness in competition, behaviour in an unsportsmanlike manner or attempt to influence the result of a competition in a way that is contrary to sporting ethics."
It is highly unlikely that tampering with a rivals' grid reference tape is officially classified as unsportsmanlike, but that would only be something for the FIA to decide if there was a formal complaint.
Gloves are off
Trying to annoy rival teams has been part of F1 forever, so it is not the first time, and will definitely not be the last, that this sort of thing happens.
What the situation speaks more of is the seriousness with which Red Bull is taking this end of season run-in.
Where once Max Verstappen's 2025 F1 title hopes appeared to be over, now he is firmly in the mix - even if he suggested on Sunday night that perfection is the only way that he can deliver this title.
"The gaps are very small," he said. "I think every weekend you need to try and be perfect, and that's what we'll try to do until the end."
Perfection will mean Red Bull doing absolutely everything in its power to not only deliver the best performance for its own car but also do what it can to disrupt its rival McLaren.
Unsettling one of the opposition before the race start fits exactly into that behaviour.
But amid the fallout of Red Bull being caught over something as petty as interfering with reference tape, it will be fascinating to see if McLaren doubles down in protecting it in Mexico this weekend - and if Red Bull continues to try to mess with it.
