A funny thing happened in Perugia vs Modena's match today. This is the first time I saw the referee shows a "green card" on court.
It's a new rule to encourage an honest player when there is a controversial judgement.
The referee signaled that Modena's spike was outside. When Modena's players are complaining to referee, Leon raised his hands to show the referee there was actually a block touch on him. So the referee reversed the judgement. It's no need to waste time on a video check. It's good for audience. In order to encourage Leon's decent behaviour. The referee rewarded him with a green card.