The international marking and tracing of certain goods is a well-established practice. However, there are no global mechanisms for the reliable tracking of weapons and ammunition from their production and subsequent transfers from one party to the next. This significantly constrains any possibility at present to identify and hold accountable those governments or people who have authorized or failed to prevent transferred, brokered, or used arms in violation of national and/or international law. It is essential to adopt a proactive approach, a robust international treaty, to making and tracing illicit small arms and light weapons. In 2003, the United Nations General Assembly launched a process to negotiate an international instrument to enable states to identify and trace illicit small arms and light weapons. In 2004, an open-ended working group met to debate the scope and contents of the instrument. This report presents the United Nations negotiations in establishing international marking and tracing controls. In addition, necessary elements for effective marking and tracing are outlined and include: the marking of arms, registration of transfers, the inclusion of ammunition, and strong review mechanisms. Governments must work together to adopt a multi-faceted approach which embeds high standards on marking and tracing arms and ammunition in a broader international legal framework to strictly control the arms trade. Appendixes 1-3 and references