This manual has been produced as part of the IAEA’s Action Plan for the Safety of Radiation Sources and Security of Radioactive Material. It is intended to: assist in the recognition and identification of objects thought to be radioactive devices, sources and transport packages; provide instruction on what to do and how to obtain further help; enhance awareness of the existence of radioactive devices, sources and transport packages; and provide information on the International Catalogue of Sealed Radioactive Sources and Devices through regulatory authorities in IAEA Member States. It will also help in identifying sources involved in events that are reported for inclusion in the IAEA’s Illicit Trafficking Database.