There is a flashing light not mentioned there fitted to many cars and that is emergency braking. Many performance cars switch on break down lights during an emergency stop.
Obviously not any of braking lights are used as that would be misleading and illegal anywhere.
(c) Any stoplamp or supplemental stoplamp required or permitted by
Section 24603 may be equipped so as to flash not more than four
times within the first four seconds after actuation by application of
Not sure about this Secton 24603, but there are circumstances where it is legal. I've seen them in Colorado, 3rd brake light will flash like 4 times within a few seconds of applying the brake then go solid.