Stop-go penalty
A stop-go penalty requires a driver to stop in their pit box for a fixed time — usually ten seconds — during which no work may be done on the car.
The no-work rule is what separates it from a normal stop: the team cannot use the time to change tyres, so the whole penalty is lost time.
It is the harshest sanction short of disqualification and is reserved for serious offences, most often dangerous driving or an unsafe release from the pit box.