RAF Diversion Rules

Hi
Can anyone confirm that the Diversion rules listed below are still accurate or if they have been modified since I Retd in 1964

Class “A” A pilot receiving a Class “A” diversion has no option, he must divert as ordered “No Argument.

Class “B” A pilot receiving a Class “B” diversion order may to go to his original destination airfield if he has a sufficiency of fuel which would allow to continue on to reach the diversion field with a safety fuel level after the attempt.

Class “C” A pilot receiving a C diversion may take it as advisory