|Abu Dhabi Grand Prix|
|Venue: Yas Marina Circuit Dates: 27-29 November|
|Coverage: Live BBC TV, radio and text coverage of the race. Full details here.|
Ferrari and the new Haas team have been cleared of breaking rules restricting research and development.
Mercedes had asked governing body the FIA for clarification on the rules governing aerodynamic testing and other ways of sharing information.
Their questions came after widespread concerns Ferrari used their links with Haas to get around the restrictions.
The FIA ruled there was no evidence any team had broken the rules, but has also closed off any potential loopholes.
The FIA conceded there were ambiguities in the regulations and has issued a series of clarifications outlining what is permitted.
Among them is a statement that any competitor planning to enter F1 should be governed by the rules on design and development restrictions from the moment their entry is accepted.
This has not been the case with Haas, who have benefited from unrestricted development during their preparations for F1 entry next year.
Mercedes and other teams' concerns centred on this anomaly - there were suspicions that Ferrari had been using time in their wind tunnel that was nominally for Haas to do work on their own car.
However, Mercedes team boss Toto Wolff said: "I am comfortable with the outcome because it gives us clarity and that was the main purpose of the exercise.
"If they gained an advantage by interpreting the rules as they did, then, 'chapeau' and they deserve that."
The FIA ruled that "there is no evidence that competitors have not complied with the requirements" of the relevant rules.
The rules govern time in the wind tunnel, data restrictions on computer design, and so-called "listed parts", which are parts of the car that a team must design themselves. These include the monocoque and all aerodynamic surfaces.