The FIA has tightened the requirements for drivers to gain a free practice licence, ostensibly meaning fewer young drivers will be able to take part in Friday practice sessions at Grands Prix.
Prior to the change, drivers wanting to participate in free practice without a superlicence were required to complete 300km (186 miles) in a "representative F1 car" and answer questions on the Sporting Regulations. If successful, a 'free practice' licence would be issued, allowing the driver to take part in Friday sessions.
From 2018 onwards, the FIA has amended those rules, with drivers now needing to have competed in six Formula 2 races or have accumulated 25 superlicence points in eligible championships during the previous three seasons, in addition to the aforementioned 300km of F1 running.
Any subsequent participation in free practice sessions requires a driver to demonstrate they have completed a full season in F2 or amassed 25 superlicence points during a three-year period.
In addition, the team concerned has to certify that they have held a briefing with their driver about the most important points of the rules, whilst the driver must be judged by the FIA to have consistently demonstrated outstanding ability in single-seater formula cars.
If the new rules had been applied in 2017, only Alfonso Celis Jr would not have been able to run.