Ulla Edberg, wife of Washington Capital forward Rolf Edberg, shopped in the Crofton Drug Fair the other day and she was asked whether she was eligible for a sales tax exemption, granted to foreign nationals employed by nonprofit organizations or embassies.

"My husband plays hockey." Mrs. Edberg replied, and the manager decided that she was required to pay the sales tax. It is likely that he made a mistake. If the Capitals are a profit-making outfit, it will come as news to owner Abe Pollin, who has poured more than $5 million down the drain in the club's four-plus seasons.

Tonight the capitals return to Capital Centre for a 7:30 date with the Buffalo Sabres, still seeking their first five-figure crowd of the season.

"We're not doing anything differently; we just need a few wins," said a Centre ticket hawker who indicated that another sub-10,000 gathering was predictable.

Coach Danny Belisle, feeling the pressures of a 2-9-3 record that has dropped the Capitals into the Norris Division cellar, at least has history to reinforce his optimism tonight when he gives his charges their pregame pep talk.

Washington has beaten Buffalo twice in 20 meetings, including a 4-3 decision in their last confrontation here April 4. During those back-to-back, tennis-score beatings from Montreal (6-0) and Boston (6-2), it was apparent even to Belisle that the first negative occurence brought the look of defeat to Capital countenances that had never basked in victory over either team.

"Realistically, we don't match up with Boston and Montreal," Belisle said. "But that doesn't mean we should lose every game to them. We ought to be able to take one out of four, at least. That happens all the time in sports.

"In both of those games, we played well initially, but as soon as something went wrong you could almost hear them say, 'Well, we were supposed to lose, anyway.' They still kept playing, but something just wasn't there anymore.

"Now that I've faced those teams, maybe I'll coach a little differently. But we have limited personnel in some areas. There are only so many things you can do. The older players aren't going to change much. If they're making mistakes now, they'll probably keep on making them, whether I point them out or not. You have to work with the younger ones and change them now, before the mistakes become habits."

Belisle said he would review his defensive alignment for tonight's game, but his comments on "older players" and "mistakes" would not seem to increase veteran Bryan Watson's chances of returning to the lineup. Rick Green is still questionable with his bruised right hand.

Buffalo, once a high-scoring club, now stands last in the NHL in that department, managing only 29 goals in 12 games.Only the superb play of goaltender Don Edwards, whose 2.55 goals-against mark ranks among the league's best, has enabled the Sabres to record 10 points.

"They're not doing the things they ought to be doing," said Roger Crozier, the Capitals' assistant general manager who scouted the Sabres in Thursday's 4-4 tie with Pittsburgh. "Their game is skating, passing and shooting. They're not doing it and they're not scoring."

Only Richard Martin, with five, has scored more than three goals. Gil Perreault has two, Rene Robert one.

The game matches the NHL's only black players, Bill Riley of Washington and Tony McKegney of Buffalo.