The FIA clarifies the single helmet design rule
A few weeks after announcing the upcoming introduction of the single helmet design rule for F1 drivers, the FIA provided more details.

The FIA has published today the details of the new rule that will prevent drivers from having more than one helmet design per season.
This modification of the regulations is intended to allow fans to more easily recognize the drivers in their cockpits. According to Article 21.1 of the 2015 Sporting Regulations, they must present a helmet with a substantially similar livery at each round of the championship.
The use of the term « substantially » will thus allow minor modifications – such as changes of sponsors or frugal touch-ups – but will no longer permit, for example, the use of special helmets.
Clarification of the rules regarding the permanent number
The FIA also provided some additional information regarding the permanent numbers of drivers leaving Formula 1. These numbers, introduced in 2014, are tied to the competitors for their entire career in the premier discipline.
However, there remained the issue of drivers who may leave and then return after a certain period of time. Henceforth, the regulation states that: « A driver’s career in Formula 1 will be considered over if they do not participate in any Grand Prix for two full seasons. » Therefore, numbers are protected for two years before they can be reselected by a new driver.
Demonstrations with cars from the current year
Finally, the last regulatory change revealed is the authorization to participate in events such as demonstrations with a car from the current year once the season is over. The regulation now states that such a demonstration « can only take place between the end of the last GP and the end of the calendar year », « cannot exceed 15km in length », and « only tires specially designed for this purpose by the designated manufacturer can be used ».