A system and method for tagging, tracking, locating and identifying people and vehicles transporting people using Perfluorocarbon tracers. An on-going problem faced by military as well as law enforcement personnel is that of friendly fire incidents. To prevent possible friendly-fire incidents, troops would separate the two layers of the uniform patch, thereby releasing a controlled release of the Perfluorocarbon vapors. Other friendly troops, equipped with sensors tuned to the specific perfluorocarbon characteristics would thus be able to literally view a plume around the tagged person or object. The system may conversely be used to tag enemies. Formulations of mixed perfluorocarbons may be used to provide coding of emissions.