One of the stranger ceremonies in recent memory will take place on Friday. At 10 o'clock that morning, the bridge that carries the Beltway over the Potomac River between Bethesda and McLean will be rechristened the American Legion Memorial Bridge.

Thousand of readers are probably saying, "Rechristened? Huh? I thought that thing was called the Cabin John Bridge."

It is, incorrectly, by just about every radio traffic reporter in town. Many of them know better, but they continue to do it anyway because they figure "Cabin John" is now firmly etched in everyone's consciousness. That's both understandable and forgivable. When you're trying to rush through the whole town's traffic disasters in 45 seconds, you tend to go with shorter names that are familiar, rather than ponderous names that aren't.

But the "Cabin John Bridge" has officially been the American Legion Memorial Bridge since it was dedicated on May 30, 1969. Friday morning's ceremony will underscore that fact -- and will be the first step in a campaign to wean the radio guys from their "Cabin John" addiction once and for all.

That shouldn't be too difficult, even when you consider how much time pressure the traffic reporters are under. If they can say Woodrow Wilson (four syllables) and 11th Street (also four), they can certainly manage "A.L.B." (three). It's not as if the A.L.B. will be overlooked. It always has more than its share of disableds, fender-benders and worse.

"A numerological curiosity" from Sue Schwartz of Silver Spring.

Her daughter Debra pointed out that the Springbrook High School senior class will graduate on 6-8-86 -- and most grads were born in '68.

More ammo for those who don't New York.

Helen Gunderson of Chevy Chase says her granddaughter once had a prep school classmate who hailed from NYC. One day, the classmate admitted that she had grown up thinking that the "D.C." in "Washington" stood for "Duh Capital."

Some Halley's Comet dialogue, as uttered in the Reston home of Len and Gail Greenberg.

Len: Knock, knock.

Gail: Who's there?

Len: Comet Halley.

Gail: Comet Halley who?

Len: Tres bien, merci. Et vous?

There's a lot of moaning and groaning at the Capital Centre these days about the failures of the Bullets and Capitals. But C.C. management has finally addressed the problem that caused the greatest number of moans and groans. At last, the Landover sports palace has enough bathrooms.

A couple of weeks ago, the Centre opened two new Big Johns -- and they are not misnamed. Each gender gets a Big John, and each B.J. is twice the size of every other rest room in the place. No one is promising that restroom lines will disappear, but at least they will diminish. Good news if you're sick of missing baskets, goals and songs as you stand there and stand there and stand there, waiting to get inside.

Like so many of us, Brendan F. Somerville of Vienna thought that computers were supposed to make routine tasks faster. But like so many of us, Brendan waitsandwaitsandwaits whenever he mails a change of address notice to a magazine -- often as long as eight weeks. His question: Why?

"When you do change an address, you interrupt a computer label-printing run that keeps track of an incredible volume of subscribers, usually in the several hundreds of thousands range," said Jack Thompson, lists manager of the Magazine Publishers Association. A spokesman for Direct Marketing, a New York City company, added that address labels contain much more information than just your name and address. All info must be coded by a person, the spokesman said. That takes time.

Good news in one way, though. At least humans are still an indispensable part of the process.

A nominee for Amen Corner, courtesy of William G. Allman of Bethesda. The scene was the upper concourse of the Friendship Heights Metro station, where a tour group had gathered.

"As I began walking down the escalator , I was pleasantly surprised to hear the tour leader tell her charges very clearly that they were to stand in a single file on the right side of the escalator," Bill writes. " . . . Now I can wish only that many of the residents of our area were as considerate."

Or as literate, Bill. After all, there's a sign at the top of every escalator telling riders that starboard is the only way to go.