FEMA Says 10-4 Isn't Always Clear 10-4 translates to acknowledgement, 10-50 means there's been an accident on the roadways. Ten codes are the language heard on law enforcement radio. Federal Emergency Management Agency officials say since those codes aren't universal between all agencies, they should be eliminated. They say the codes have the potential to slow response time or send mixed messages. Eau Claire's police chief says in situations that have multiple agencies responding, officers will stay away from code. "I think in your day to day operations, agencies are still using portions of it, but when there's a large...