Police slang can look a lot different from city to city. People all over the country have many different names for police. Words like cops, po-po, and 5-0 are commonly used terms to refer to the boys in blue, but Atlanta has its own commonly used term that has now become widely used in pop culture.
Police in Atlanta are called 12 as a slang term. According to sources, 12 comes from the police radio code “10-12,” which means thats visitors are present in the area where police are going. It’s similar to a warning to police that they might have company when they arrive on the scene. If you ask Urban Dictionary, many folks have different definitions for the slang term and where it originated.
It’s used in the streets to give a quick heads up to friends and or civilians that police have arrived or they are on their way. It’s is mostly a Southern, United States slang term, but has been adopted by television shows as well as pop-culture.