The dividents of Potomac Electric Power Co.'s stockholders and the electric bills of Pepco's customers in Washington are at stake in a battle of legal briefs.

Pepco is on one side, the District of Columbia People's Counsel on the other, and fundamental changes in the way electric rates are set are likely to result regardless of who wins.

The score is one-up, with People's Counsel Brian LEderer winning one round last Friday and Pepco another yesterday.

The issue is how much information about Pepco's internal decision-making ought to be made public, or at least made available to the People's Counsel.

The People's Counsel - a government paid consumer advocate - set up the confrontation by asking the District of Columbia Public Service Commission to require Pepco to produce a mass of records.

Pepco was asked to provide information about its sales of surplus electricity to the Pennslyvania-New Jersey-Maryland power pool and to reveal all the financial information on which its rate requests are based. Specifically, the People's Counsel asked about how much profit - per share - Pepco expected to make and when and how much additional stocks or bonds it would have to issue.

Since the future earnings outlook is about the most sensitive information in a company's books - and projected stock offerings are on the same page - Pepco was predictably upset. The utility said it would be in trouble at the Securities and Exchange Commission and on Wall Street if such facts got out.

Lederer offered to keep the data confidential but insisted the fiscal projections are "probably the mot sensitive, critical information" involved in evaluating rate requests. "It's at the heart of the ability to protect the customer."

The PSC yesterday refused to required that kind of information to be given to the People's Counsel. But last Friday it gave Lederer access to most of the facts he sought about the operations of the power pool.

Pepco sells surplus juice to the pool, and credits the earnings against the fuel adjustment charges on all electric bills. Pepco says that saves customers money; Lederer questions whether it saves them enough.

Pepco executives complain that Lederer's information requests are "a fishing information" and got the PSC to limit the requests. Even so, claims Pepco spokesman Horace Webb, there's a 15-foot stock of files involved and most of the information requested is "totally unreasonable and irrelevant."

While the taxpayrs are paying the People's Counsel's expenses, the electric ratepayers are picking up the bills for Pepco's side of the case, since legal costs are part of the utility's expenses. Already Pepco says it has spent thousands of manhours sparring with the People's Counsel. Now it's adding up the costs.

If a going-out-of-business sale ever can be considered successful, Giant Department Stores ought to qualify. Giant was able to pare its inventory in the four stores down to $2.9 million with discounts of only 25 per cent, holding to that level for three weeks.

Now the company says it has $1.8 million in merchandise left and is cutting deeper to move out what's left. The hardgoods departments have been decimated by now, and the stores probably will be emptied out at least two weeks ahead of Giant's late February deadline.

Equally important, Giant vice president David Sykes said there are active negotiations with tenants for three of the locations and preliminary talks on the fourth.

Regardless of which big retailer moves into the Giant stores, it will shift the market share of the Washington-area discount store business.

Giant would like to sublease all four of its department stores as a package. But the most likely candidates - Korvettes, Memco and K mart - are next door to at least one of the Giant locations, so none is likely to take the whole deal.

Woolco - the discount department store operation of F.W. Woolworth - is preparing to take over a couple of locations where Dart Home Centers have been consolidated with nearby Dart Drug stores.

Woolco recently announced a corporate strategy of clustering its stores in markets for maximum impact, fueling speculation that it would need more than its current four stores - or even the six it would have with the Dart Home locations - to fully cover the Washington market.

You should have seen it coming, when Sidney Lewis, after announcing he was moving. The General Store from 18th Street and Columbia Road, NW. to 801 7th St. NW, switched signals and kept both stores open.

Now he's got a third General Store, at 2834 Alabama Ave. SE. Like the others, it's a jeans and casual clothes mass merchandising emportium, located in a low rent facility in a neighborhood largely ignored by other retailers.

About the time General Store No. 2 opened, Lewis, who's credited with firing some of the opening shots in the Great Jeans War, decided to stop talking about his business, so a lot of questions are unanswered.

Does the formula work? Would there be three General Stores if it didn't? Will there be more? Is Sidney Lewis the son of the entrepreneur who built Best Products into a giant catalog showrooms?