The Explosives Tagging Program of the Bureau of Alcohol, Tobacco, and Firearms is a research and development program to tag explosives so that they may either be detected before they explode or may be traced after an explosion. The overall goal is to reduce deaths, injuries, and property damage from bombings. If the U.S. Congress passes legislation requiring manufacturers to tag explosives, an identification tagging system developed by the 3M Company may be used. Explosives will be mixed with nine-layer plastic (melamine alkyd) particles from 40 to 400 micrometers in length. Each layer is colored with any 1 of 10 pigments to conform with the Universal Electric Code, providing a series of numbers coded to relate to specific production units of manufactured explosives. To help bomb-site investigators, some tags are made with a layer that fluoresces under ultraviolet light. The tags appear as specks of light in bomb debris. A magnetic layer allows the tags to be extracted with a magnet. Detection tags would allow the discovery of unexploded bombs. Such tags would release vapors from microcapsules for at least 5 years -- since most explosives are used within this period. The vapors are perfluorocarbons that may be detected by electron capture detectors, ion mobility spectrometers, mass spectrometers, and possibly animals. In the future, computer-assisted dual-energy tomography may detect explosives not tagged. The current status of legislation is reviewed. A table, diagram, and photograph are included.