Each fuel handling vehicle shall be conspicuously marked in letters of contrasting color, with the word “Flammable” on both sides and rear of the cargo tank in letters at least six inches high, and with the wording “Emergency Shut Off” and other appropriate operating instructions at the location(s) of emergency operating devices in letters at least two inches high.
(Res. No. 149 75-76 (part), Res. No. 68 86-87 §1 (part))