Ace the AMMO Block 4 Exam 2026 – Fire Up Your Knowledge and Hit the Target!

Placards are a way to communicate explosive hazards during transport. When items are on a base and not being moved off-site, transport-specific markings aren’t needed. The signs that indicate the material’s transport hazard—HD1.4 (the Hazard Division for this class of explosive) and the Compatibility Group—are the ones omitted for on-base storage. This is because those markings are tied to movement and how different items can be safely combined during transport, not to base storage. The other options either aren’t placards (a regulation), refer to non-placard concepts, or are too general to be the ones specifically omitted in an on-base scenario.