When it peeves, it pours. The other day, within an hour, two of my least favorite "little annoyances" cropped up.

But after a couple of phone calls, explanations did, too. So if you've been boiling over because of these two peeves, console yourself. Even if the no-good so-and-sos are driving you crazy, they have reasons.

Peeve One: I had to mail a letter to a business in Hyattsville. I looked up the address in the white pages. Then it came time to add the Zip Code. Which I didn't know.

So out came the Yellow Pages. Near the front of each edition, C & P Telephone publishes rather crude maps of the borders of all the Zip Codes in the metropolitan area.

But as always seems to happen, I had no idea whether Ager Road and Hamilton Street in Hyattsville lay within 20782 or 20781. Neither street is a border of either Zip Code, so it didn't appear on the map. To hurdle this roadblock, I had to waste 30 seconds or so by calling the business and asking the switchboard operator what the Zip Code was.

Which, from C & P's point of view, may be the whole idea. But if the phone company prints street addresses opposite individual listings, why can't it print Zip Codes?

Because the company would be courting an enormous increase in the cost of printing and reprinting phone books, according to a company spokesman, Web Chamberlin.

"We're in the business of providing number service and not address service," Chamberlin said. "Zip Codes are subject to being updated and changed. That would mean we might have to reprint our books more often. That could increase our costs by up to 40 percent."

And guess who would pay that.

Chamberlin did note that a business can elect to have its Zip Code appear next to its listing in the Yellow Pages. The additional cost is $2.25 a month in the District and Northern Virginia, and $2.75 a month in Maryland.

In addition, Chamberlin pointed out that the Washington post office maintains a special Zip Code information number (523-2375). It is manned or womanned 24 hours a day, and will give you the Zip Code for any street address in the country.

Peeve Two: the parking lot attendant went to get my car. He was about the same height as I am. When the car arrived, the driver's seat had been scooted so far forward that I could barely get into the car.

After delivering a car, can't attendants at least move the seat back to approximately where it was? And if not, why not?

I consulted my authority: Cornelius Johnson, Mr. Service with a Smile (and without a Scooted Seat) at a downtown garage near The Post that I use frequently.

"Better safe than sorry," he explained. "Lot of the guys know they'll be fired if they crash up any of the cars. So they make sure they can reach the pedals.

"And most of the time, the only reason they don't scoot the seat back after they bring the car is that it's rush hour and 15 other people are waiting for their cars. One time I was putting the seat back and some lady says to me, 'Can't you see I'm waiting for my car? Let him put his own seat back.' You make 'em mad, they don't tip."

So there you have it. Any other peeves? I'll hunt for explanations.