Ten-codes were developed in the 1940s at a time when police radio channels were limited, to reduce use of speech on the radio. Experienced radio operators know that the first syllable of a transmission is frequently not going to be understood, but is a necessary part of "tuning in"; hence preceding every code with "ten" allows a better chance of understanding the critical portion. Ten-codes were later adapted for use by CB radio enthusiasts before its pop culture explosion in the late 1970s.
In the fall of 2005, responding to inter-organizational communication problems during the rescue operations after Hurricane Katrina, the United States Federal Emergency Management Agency (FEMA) discouraged the use of ten-codes and other codes due to their high variability in meaning. The Department of Homeland Security reportedly has plans to do away with 10-codes as well, in favor of "Plain English" while the nationally-standardized Incident Command System specifically prohibits ten-codes. As of 2008, ten-codes remain in common use.