When Nelson Joyner showed up in Washington as an American Standard Corp. executive on loan to the Commerce Department, the first thing he learned was the extraordinary amount of information about almost any business that is available from the federal government.

And the second thing he learned was ferreting out those meticulously filed facts is a near impossible job for anybody who's not a bureaucrat.

Joyner's answer, several years and a couple of careers later, is a book called Joyner's Guide (to official Washington).

At $95 a copy, Joyner's Guide may not be a best seller, but it has gone into its fourth edition. As a tool, it's as useful as the Congressional Directory, department phone books, or the Directory of Key Government Personnel published by Hill and Knowlton. (That little blue book would be a best seller if the big public relations agency didn't give it away.)

The guts of Joyner's Guide is a subject index to the federal government. Want to know who at Commerce knows about Japanese exports of plumbing fixtures? the book gives names and phone numbers.

The book is written for business people, not politicians, so the sign posts don't point to the usual Capitol Hill aides. Instead they guide readers to career government people, who provide answers regardless of whose district the caller lives in.

Mostly Joyner is concerned with foreign trade, so that's the thrust of the guide. Businesses interested in exporting a particular product can find who their competition is, locate likely foreign customers, wend their way through the export regulations and line up financing with government help.

The guide is a major project for Joyner and Associates, a Reston consulting firm. Joyner himself is now working for American Export Group, using his own guide to facilitate the company's exports of building materials to the Middle East.

SHOPLIFTERS NOTE: For the first time in six years, Woodward and Lothrop has broken the upward trend in inventory shrinkage, the retail euphemism for theft that costs big chains millions of dollars a year.

Woodies' new president Waldo Burnside gave stockholders the good news at the company's annual meeting Monday.

Later he said the "shrink" was down on half a percentage point, a difference that means hundreds of thousands of dollars a year.

No, they're not volunteering to tell how they did it. Nor is Woodies yet talking about its new corporate identity program. But later this year look for a new logo plus all the shopping bags, signs and paraphernellia that go with it.

The sexier image completes the modernization of the chain's major stores, which are undergoing an expensive face lifting and should be rid of their wrinkles by the end of the year.

SUNDAY HOURS: The District of Columbia Savings and Loan League will meander over the mountains to Hot Springs, Va. this weekend for its annual convention, preparing the Homestead for the D.C. Bankers' spring bash two week later.

While other S&L executives are recovering from Saturday night's black tie gala by taking the waters next Sunday morning, the staff at Standard Federal Savings and Loan will be unlocking the doors for another day's work.

If drug stores and supermarkets, Georgetown boutiques and Prince George's home builders can do business on Sunday, why not a savings and loan?

Why not? asks Marshall Rachmiel, branch coordinator for Standard Federal.

So he started opening the branches in Wildwood Shopping Center, Aspen Manor and Langley Park, from 10 a.m. to 3 p.m. on Sunday a few weeks back.

"We're basically retailers," he explained."We're in the retail money business. The lifestyles of the people we serve are such that they can't get everything done in six days."

Sunday is the busiest day at the Wildwood branch, although Rachmiel concedes that Sunday openings are not planned for all of Standard Federal's nine branches because, "location is critical."

Other S&L officials say Standard Federal's move is not a trend.