Not a term used in dealing with ammunition. The US Military uses 10 classes of supplies- and all ammunition and explosives are class V (five). Please repost your question with additional information, we will try to answer it. If your question involves a game, it may be a made up term with no real life meaning.
Easily. Australia has developed excellent emergency management programmes which, together with higher building standards, limit the damage done by cyclones. Australia experiences over a dozen cyclones every year along its coastline, and many of these are category 4. Examples of category 4 or higher cyclones which Australia has handled include Cyclone Yasi - 2010 (category 5), Cyclone Ingrid - 2005 (category 4/5), Cyclone George - 2007 (category 5). Cyclone Tracy was a category 4. The reason it devastated Darwin was that this was before current cyclone standards were put into place.
CATEGORY 4
it deals with manufacturing of arms and ammunitions
THIS question is clearly in the wrong category.
Grenades
category 4
Category 4.
Hurricane Ike is a category 4 hurricane.
Armors and ammunitions
Bullets and ammunitions
Cultural
networks