At Ed Haynes' Dupont Circle area laundromat, the do's and dont's are clearly spelled out on the wall.

"It is forbidden by law," declares one in a long row of vividly illustrated, hand-lettered signs, "to consume alcoholic beverages on the premises."

Underneath, for the benefit of non-English-reading patrons, a broad black line has been drawn across a glass of wine and a can of beer.

"Please remove garments from machines promptly when cycle is completed," urges another sign. "Pets are not permitted on the premises please," proclaims still another.

Additional signs suggest the inadvisability of loitering, littering or leaving miscellaneous items like newspapers and detergent boxes on top of the washing machines.

On the other hand. "Customers are permitted to remove clothes from any machine that has completed its cycle." And the management has posted a supply of refund forms, plus a box in which to deposit them, for customers with complaints.

Ed Haynes, the management, is often to be found on the premises, performing preventive maintenance on touchy appliances, chewing out disorderly patrons, or shooting the breeze with his friends. Even when the laundromat is left untended. Haynes usually can be reached -- and, if necessary, fetched -- through a special telephone hot-line to his office across the street.

Few businesses reflect their proprietors' personalities as strongly as Haynes' laundromat reflects his.

Haynes is a bearded, 45-year-old veteran of 10 years' service in the U.S. Army and of a meager Mississippi upbringing. Although he recently received a bachelor's degree from Federal City College, he originally left school in the third grade, to become, successively, a "bellboy/all-around man" at a hotel, a clerk for an office supply store, a delivery-boy for a Chinese grocery, and a movie theater projectionist.

He had a tendency to get fired in those days, he recalls. The Chinese grocery fired him several times, "because I would take the truck and do one delivery and then I'd stop off at the pool-hall and lose the money. A movie theater fired him when he inadvertantly set the projection booth on fire.

Fed up with Greenville, Miss., and a salary of 50 cents an hour loading railroad boxcars, Haynes enlisted in the army at 17. During two separate stints interrupted by five years of marriage and civilian life in Los Angeles, he was sent to Japan, Korea and Germany, and wound up in Washington with the rank of sergeant, first-class. His last assignment was setting up outdoor public address systems for President Kennedy and other federal dignitaries.

The military has left its imprint on Ed Haynes and on his place of business. "He runs a tight ship," says Clark Mishler, a layout editor for the National Geographic Society. "He doesn't take any guff from anybody. IF you give him any trouble he bounces you out on your butt."

Mishler lives six blocks away from Haynes' laundromat at 1722 Connecticut Ave. NW., but feels it's worth the trip. "There's one (a laundromat) real close," says Mishler, "but there's no way to contact the owner." At Haynes', "Everything works, unlike other places where. . .you might leave a note and say, hey, this machine ain't working right, but you come back a week later and it's still the same old machine."

Haynes constantly is checking his machines, for which he has an ample supply of replacement parts, including spare dryer motors, neatly shelved away in the rear.

Maria Hopkins, an art student at the University of Maryland, has only one complaint -- the prices. Haynes charges 75 cents for a wash, and 25 cents for 10 minutes of drying time. "I'm still used to 35 or 30 cents a wash," she says.But "when it says hot water, you get hot," she adds. "All of the machines are operable. Most of the laundries I go to I lose at least 50 cents in machines that don't work."

Liz Reid gets up early every Sunday morning to beat the crowd. Usually she uses about four machines at once. Today she is using six. "I just got back from a camping trip in the Virgin Islands," she explains. "So everything I had was full of sand."

What she likes about Ed Haynes' laundromat is that "even if there's a fight over the machines it's resolved fairly amicably." When Haynes is on the scene, however, there are no fights -- anyone who tries to use a machine out of turn is politely, but firmly, shoved aside by the management.

"He's very strict," says writer Christopher Klose, a frequent customer over the five years that Haynes has run the laundromat. Sunday mornings have calmed down some since the old days, says Klose, when "it turned into a battle between the Hare Krishnas with their robes, and the rest of us."

Haynes views his customers as a "good group, even thoughts sometimes I may raise hell with some of them. I have learned that people are doing to be people. Some people will spill detergent on the steps or something . . . Sometimes you get mad at people and you just have to bite your tongue."