This police code infographic explains the meaning of the codes that emergency personnel use to communicate in the US. Emergency communication uses codes such as the ten, eleven and thirty seven codes as well as the phonetic alphabet as a way to shorten conversations. Additionally, codes are use to mask communication meaning from those that may listen to police communication such as criminals, reports and those with a police scanner radio. This guide briefly explains the history of police codes and define their meaning today. While code definitions vary geographically, this guide provides the most popular and most common codes used by US emergency personnel.