California LE transplant here... I'm surprised to read here that police agencies located outside of California use California penal and vehicle code numbers in their radio communications. Don't they have their own, unique statute numbers? "Code" is a misnomer in California because it is more than just a radio code, like 10-4 or a Code 6. "Code" in California means using the statute numbers of the penal law or vehicle law in question. Such as 211, 459, etc.
Not only does California use penal and vehicle statute code numbers on the radio, they also have them on a subject's criminal and driving records, too. Not plain language, just a series of penal/vehicle code statute numbers with dates of arrest/citation, convictions, etc. Until they all get memorized, one needs a guide book to decipher what all the statute numbers mean. Good practice. Impress your friends at parties. NOT!
Other than some very generalized radio codes (not based on statute numbers), I doubt that there is much in common between different agencies nationwide, especially those like California that use statute numbers to refer to their crimes & violations.