The FIA World Motor Sport Council has added more detail to plans to hold standing starts in wet weather conditions.
Previously if conditions at the start of a Grand Prix are deemed too poor for a conventional start, the race had a rolling start behind the safety car. Once race control decided the track was ready, the safety car pulled in and the cars start racing.
Under the new rules, cars will still get underway behind the safety car on full wet-weather Pirelli tyres. The first lap will now be an additional formation lap and not count toward the race distance.
Any driver who is delayed in initially getting underway will be allowed to overtake cars in front "to re-establish the original starting order or the order the cars at the pit exit were in when the formation lap was started." If they're unable to do so in time they will have to start from pit lane instead.
Drivers already due to start from pit lane can still circulate behind the safety car to get a feel for conditions. However they will not be obliged to and can opt to sit and wait if they prefer, and conserve fuel. When it's time for the race to start they will have to come in and start from the end of pit lane.
Any driver who pits during the initial safety car period will have to start the race from pit lane. Other drivers will not be allowed to follow the safety car when it comes in to pit lane and can't take on fresh tyres for the start. If they do, they'll get a ten second stop-and-go penalty.
Once race control deems conditions have improved, the safety car will pull in. Cars will then line up on the grid. If conditions don't improve then race control can opt to recall all cars to pit lane to wait it out.
As the race has not officially started at this point, it will not count as a suspension. However in these circumstances there won't be a second attempt to line the cars up on the grid. Instead of a standing start, the race will begin under traditional safety car rules.