FIA clarifies radio clampdown for F1 teams
"Italy's Autosprint said information about the operation and function of energy-recovery is not allowed, as is notifications about tyre temperature, clutch settings and brake wear - among many other instructions outlined in a detailed document. Additionally, any messages that appear encoded are not allowed. It means that only basic radio messages are now permitted, including time gaps, positions, traffic and verbal encouragements such as "push".
Discussions about the selection of tyre compounds and wing adjustments, and the type of tyres used by competitors, are permitted, as are notifications of technical problems and race strategies. Teams may also remind drivers to be aware of hazards, including the white line when rejoining from a pitstop and the limitations of the track.
And the ban will be in effect throughout not only the Grand Prix but also qualifying and practice sessions, Autosprint added." - Motorsportdotcom