What information must a placard NOT contain to remain compliant?

Placards follow a strict standard. The placard is diamond-shaped, displays the hazard symbol (a flame, ball-on-fire, skull, etc.), shows the hazard class number, and may show the four-digit UN/NA identification number in the center white area. Decorative or extraneous artwork that obscures any of the required elements makes the placard non-compliant. The reason is simple: at a distance and under emergency conditions, the placard must communicate hazard information instantly through standardized colors and symbols. Customization defeats that purpose. Placards must also be in good condition (no fading, peeling, or damage), be the right size, be properly affixed, and be visible from the direction they face.