If you've ridden D.C. cabs lately, you're well aware that many drivers are Moslems. But should they advertise their religion on the outsides of their cabs? An anonymous reader thinks not -- and wonders if the law thinks not, too.

She writes that she spotted a cab on Connecticut Avenue near the Washington Hilton Hotel the other day. Right smack in the center of the rear window was a bumper sticker that read: I ALLAH

"Aren't cabs supposed to be free of such stuff?" my reader wonders. "What's wrong with the inspectors who let this proliferate?"

Researcher Michelle Hall put the issue before Howard Davenport, general counsel of the D.C. Public Service Commission. The long and the short of it is that the law does not specifically apply to bumper stickers like the one my reader saw.

The law is crystal clear on the subject of advertising. It says that "no advertisement or advertisement device shall be placed on or in any taxicab . . . ." A bill that would undo this law is now before the City Council, but it's mired deep in committee.

Brother Davenport found another provision that might apply to I ALLAH -- but that also might not. It reads:

"No signs or other matter shall be affixed to any taxicab except as may be authorized by the Public Service Commission."

I ALLAH is certainly "matter." But Howard points out that no one has ever brought a case to test whether "matter" specifically includes religious items. Without such a test case, he says it's unclear whether the regulation as written would ban religious bumper stickers.

My vote would be to permit any such sticker, as long as it's within the bounds of decency.

I've never heard of a passenger objecting to a religious medallion dangling from the rear view mirror or to a religious decal on the dashboard. These are obviously viewed by passengers as legitimate free expression. So why not permit the same freedom on the outside of a cab as on the inside?

How many times have you seen it? Someone walks out of a downtown hotel and asks the doorman for a cab. Up zooms a cabbie who's been "sitting on the stand" for at least half an hour, hoping like the dickens for a run to Dulles Airport.

But this passenger is going only four blocks, for a grand total of $1.80. So, quick like a bunny, the cabbie trots out a tried-and-true lie.

Oh, gosh, I just noticed I don't have any gas. Sorry, mister, but my cooling system seems to be on the blink. Okay, I'll take you, but do you realize that the rush-hour fare applies to that block, and it'll cost you $10?

Or, all too often, a flat, angry refusal -- and a squeal of rubber.

A hack inspector would step into the middle of such blatant bullfeathers and inform the cabbie that he's breaking the law. But where are the inspectors? They camp out at Union Station, the major tourist attractions and occasionally along K Street. But they're almost never seen at the major hotels.

Why not try stationing an inspector fulltime at each of The Big Five: The Washington Hilton, the Capital Hilton, the Mayflower, the Shoreham and the Sheraton Washington?

Some of the busiest cab-boarding sites in town would be spared hassles and ugliness. The least knowledgable passengers -- out-of-towners -- would get needed protection. Best of all, some of the rottenest apples in the cab business would get the message.

And the hotels wouldn't mind a bit. Said Len Hickman, executive vice president of the Hotel Association of Washington, D.C., when the idea was put to him:

"I wouldn't oppose it, and neither would my members."

How about it, D.C. Public Service Commission?

Halloween impends, and so does the annual spate of stories about kids who bite into an apple or a candy bar only to discover that some wacko has placed a razor blade or a straight pin inside.

To the rescue: D.C. General Hospital. On Oct. 31 and Nov. 1, between 6 and 9 p.m. each night, the hospital's radiology department will X-ray Halloween goodies for kids (and parents) who want to be on the safe side before taking a chomp.

The hospital is located at 19th Street and Massachusetts Avenue SE. Metro's Stadium/Armory station is only a few yards away. And don't worry about the X-rays costing you an arm and a leg. The service is free.

From John Carlson of Chevy Chase: The trouble with political jokes is that they sometimes get elected.