From a press release issued by the FIM:

Road Racing World Championship Grand Prix
Decision of the Grand Prix Commission

The Grand Prix Commission, composed of Messrs. Carmelo Ezpeleta (Dorna, Chairman), Claude Danis (FIM), Sito Pons (IRTA) and Takanao Tsubouchi (MSMA), with the presence of Paul Butler (Secretary), in a meeting held this morning, has unanimously decided to introduce the following modifications to the Road Racing World Championship Grand Prix Regulations, for immediate application:

2.6 Fuel Tanks

2.6.4 Except for the case that a fuel tank is fixed on the chassis with bolts, all fuel lines from the fuel tank to the engine/carburetor system should have a self sealing breakaway valve. This valve must separate at less than 50% of the load required to break any part of the fuel line or fitting or to pull it out of the fuel tank.

This rule is mandatory for the MotoGP class.