Radio restrictions after red flag?

[hinteshbro7]

Listening to Hamilton's team radio, and the commentators, it was mentioned by bono for Lewis to look for the boards to tell him whether a standing or rolling start was required, due to radio restrictions.

Anyone have any idea why this was?

[hollus]

With the standing start it became a second formation lap, and radio comms to the driver are (kind of) forbidden during formation lap. Remember how Magnussen got a penalty for discussing pitting during the formation lap a few races ago?