Ferrari has proved to be one of the most innovative Formula 1 teams this year when it comes to aerodynamic developments.
It caused a stir in pre-season testing when its SF-26 appeared with a unique exhaust wing, exploiting a design choice with its gearbox and rear crash structure to fit an extra winglet that improves airflow around the diffuser area.
Then it revealed its flipping rear wing, which rotates its upper element through 180-degrees when active aero is deployed to help reduce drag on the straights.
While both these ideas were well understood and accepted by rivals as being wholly within the regulations, the same cannot be said for its halo wings that appeared at the Chinese Grand Prix and triggered legality discussions with the FIA.
Here we take a look at what piqued the governing body's interest and the regulations that are at the heart of the matter.
On for the sprint, off for the grand prix
The small winglets, fitted to the side of the halo's central pillar, were aimed at helping optimise airflow around the drivers' helmet and cockpit, delivering benefits downstream and helping contribute to a bit more downforce.
But while the halo wings were fitted to Lewis Hamilton and Charles Leclerc's cars in practice, and used for the Shanghai sprint race, intriguingly they were removed from the cars ahead of main qualifying and the grand prix itself.
As first revealed by The Race, Ferrari took the wings off following some discussions with the FIA.
Although both cars passed scrutineering after the sprint with the wings in place (although according to the official FIA documents these specific components were not checked), sources have revealed that it was subsequent questions from the governing body that set in motion Ferrari's decision to remove them.
The legality questions
Amid the probing from the FIA about the material rules and windscreen compliance elements, Ferrari took the decision itself to remove the wings.
It is understood it did not want to waste time debating rule interpretations on a busy sprint weekend.
And, more critically, it did not want to face any risk of a good result being protested afterwards for the sake of something that was ultimately only worth a few hundredths of a second.
Playing it safe, based on the strength of its 2026 car anyway, also means Ferrari can use the time after the China race to get better clarity on whether its legality arguments can convince the FIA.
Teams have been known to seek some aero gains from windscreen tweaks, such as the serrated edges we have seen on the Mercedes and McLaren cars.
However, we have never seen a 'windscreen' shaped like the Ferrari halo wings before.
Whether Ferrari attempts to argue its case in the future to bring the halo wing back remains to be seen, and the grounds that the FIA needs convincing over are now well known.
But it may ultimately conclude that the battle is not worth fighting for something that brings minimal benefits.