Continuous reprimands for drivers are now going to lead to 5 place grid penalties according to Adam Cooper's Blog. Once it's rubberstamped it'll be in place from Silverstone.
It is to be introduced in order that reprimands, given out to drivers for excessive speeds under yellow flags etc., will have a punitive effect and thereby discourage such behaviour.
Three reprimands will see an automatic 5 place grid penalty.
Reprimands can be given to a driver for any number of reasons apparently but, in the case of the grid penalty, at least two must relate to driving.
In Yellow Flag situations which do not merit a safety car it would be easier to program a yellow flag speed into the cars for each track which would be initiated by each driver entering the yellow flag zone and switched off upon exiting - much like the speed limiter in the pitlane. In that case any failure to initiate the speed limit would result in a black flag.