No / The illegal proliferation of small arms and light weapons (SALW) is a global problem, and one consequence of this illicit trade is that regions can become flooded with these guns before, during and following a violent conflict. Effective tracing of these arms requires adequate marking and record-keeping systems as well as improved international co-operation by relevant authorities. This publication argues that the main obstacles to progress in this area are political in nature, rather than technological. Other issues discussed include: the selection of categories and types of SALWs for inclusion in a tracing mechanism; and the structures and institutions required for an effective firearms tracing system.