Arms carriers (AC) play the central role in armed conflict and other situations of armed violence. Consequently, they are in the unique position of both causing victims and becoming victims, of being able to facilitate humanitarian operations and to hinder them. The present guide provides you with a basic knowledge of the arms carriers you will have to deal with as an ICRC delegate. Part 1 contains tips on how to approach arms carriers. Parts 2 to 5 provide information on the different categories of arms carrier (armed forces; police and security forces; other weapon bearers; private military and security companies). Part 6 is a glossary of terms related to arms carriers.