A couple of months ago, Metro public affairs officials were casting about for a Washington Redskins player to star in a please-don't- vandalize-the-Metrobuses poster campaign. The Redskins offered up Doug Williams, who at the time was gathering splinters in his hindquarters on the Redskins' bench.

Doug Who? Well, thought Metro, any Redskin is better than no Redskin. So they shot the photos and made up the posters.

The posters went up in the buses shortly before the Super Bowl. When Williams set all sorts of passing records in leading the Redskins past the Broncos, and suddenly blossomed as the most popular athlete in town, Metro's Poster People looked like the most timely of geniuses.

Now they're the unwitting victims of Doug Williams' notoriety.

Seems Redskin fans are so delighted to see Super Doug smiling down at them that they're scrawling WE'RE NO. ONE! and GO SKINS! right across his face.

A word, please, to service people.

Most of you are absolutely super. You wipe your feet on the way in and on the way out. You say please and thank you. You ask before you use the phone. You're choir boys and choir girls, through and through.

But when you're not, even the slightest slip can cause big trouble.

So it went on the night of Feb. 2 in Bethesda. Phone company workers came to the home of Rob and Cheryl Weiner to install a phone line. When they finished, they left the back yard gate ajar. It had been closed firmly when they arrived.

Buffy, the Weiners' 16-month-old cocker spaniel, took this as an invitation. Out into the rainy night she went. When the Weiners realized what had happened, and managed to locate her, Buffy was huddled in fear under a car at Massachusetts Avenue and Little Falls Parkway.

The Weiners would like to extend thanks to the two drivers at Mass and Little Falls who noticed Buffy and carefully avoided running her over. They'd also like to underscore the moral of this story: If you're a service person, and you encounter a gate that's closed, it's closed for a reason. And it should be reclosed for the same reason.

Robert, Robert, Robert. Don't you know better than to wade into the subject of numbers?

Aren't you the guy who got a D in statistics? Aren't you the guy who fell asleep in calculus? How can you write about Roman numerals and expect to get it right?

Folks, I didn't get it right.

In an item last week, I declared that MCMLXXXVIII (1988, if you prefer) has as many Roman digits in it as a year can have.

Jay Christman called bright and early to point out that 8888 would have 20 Roman digits. Richard Bachmann of Wheaton called to point out that 1888 had one more Roman digit than 1988. Preston Hewitt of Arlington called to point out that 2288 will have more digits than 1988. And so on -- to the point where the Post's phone operators have once again ceased speaking to me.

Sorry, gang. Never again. XIV lashes with a wet noodle.

And while we're righting wrongs . . . .

In a recent yarn about the famous World War II correspondent, Ernie Pyle, I said a photo of Pyle had been shot on Iwo Jima.

It was actually shot on an island called Ie Shema, which, as you can tell, sounds mighty similar to Iwo Jima on the phone. But similar ain't the same as same. XIV more lashes . . . .

Last Thursday's account of the Bloody Beggar brought forth calls from dozens of readers who have been approached by the same guy. Apparently his story changes from time to time (some days he wants money to get to Baltimore, some days it's Atlanta). But the bloody nose and the gosh-I-just-got-mugged never change.

One call was from a Metro police officer. He said the Bloody Beggar has been working every station on the Red Line. The cops would dearly like to put him away. If you are approached by this man, please let the Metro police know at 962-2121.

Thanks, Mary M. Stolzenbach of Vienna, for word of a cafeteria and sandwich shop in a Fairfax County office building. Both are reachable through a door that reads LOADING DOCK.

And thanks, Larry D. Simpson of Northeast, for this bit of dialogue.

Coworker: How many vacation days do you get?

Larry: Fourteen, plus the days my boss takes.