Must the compatibility group letter be displayed on Class 1 (explosive) placards? RegSenseHazmat PlacardingBest ResultsFAQHazmat markings, Placards, and LabelsEnglishFocus AreaUSA
The compatibility group letter is only required on Class 1 placards when a shipment of Class 1 materials is by aircraft or vessel.['Hazmat markings, Placards, and Labels']['Hazmat Placarding']