What constitutes unexploded ordnance?

Unexploded ordnance (UXO) refers specifically to ammunition or explosives that have been prepared for action but have not detonated. This includes items such as bombs, shells, grenades, or mines that were either deployed and failed to explode or were deployed mistakenly. The significance of this classification lies in the potential danger these devices pose, as they may still be functional and capable of detonation if disturbed.

Understanding this definition helps clarify that items which are simply unprimed or non-functional don't fit the definition of unexploded ordnance, as these do not retain the potential for detonation that UXO does. The focus is on those ordnance pieces that were intended to be used but failed to do so, rather than those that were never intended for use or are no longer functional.