Dear Cecil: Every so often I see a car with a license plate holder that says "Los Angeles" above the plate and "KMA367" below it. The first time I encountered one of these things, I assumed it was a ham radio call sign. Having come across the same thing on dozens of other cars, however, I've discarded that interpretation. The most plausible explanations I've heard is that it is a license-plate dating service or a system for identifying the personal cars of law enforcement officers. Neither interpretation is diabolical enough for my tastes. I'm counting on your to spill the horrible secret. Alan Levin, Los Angeles

Cecil replies:

Cecil hesitates to address these purely local issues, preferring to devote his attention to questions that at a minimum affect an entire galactic sector. But I used to wonder about this myself, and besides, let’s face it, the LA cop situation, which is in fact what we’re talking about here, has achieved a certain global notoriety.

KMA367 is the call sign of the main LA police radio transmitter, something most cops know but most ordinary folks don’t. So some shrewd entrepreneur began selling KMA367 license plate holders through the LA police academy store. An LAPD spokesman tells me the purpose of the plates is merely to identify your personal vehicle to fellow cops while not advertising it to the world at large. Similar license plate holders are used by other SoCal police orgs. But some cynics out there believe that at least one or two of the cops who bought the holders figured other cops might give them a pass next time they got a little heavy footed on the freeway.

In time, word of the KMA367 code began leaking out to the civilian (i.e., noncop) population. Folks began buying used KMA license plate holders at garage sales and such, and you can always walk into the police academy store and pay full retail. Whether because the identificatory value of the holder is diminished or simply because all LA cops are virtuous, the LAPD spokesman says a KMA holder isn’t going to do a damn bit of good preventing you from getting pulled over for traffic violations. Still, these days you’d be foolish not to take advantage of any break you can get. I bet Rodney King wishes he’d had a KMA license plate holder. I bet most of LA wishes he’d had one too.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.