Collection of the new tax on sweets and soft drinks began in a crazy-quilt fashion in the District of Columbia yesterday as the city's finance chief admitted her agency goofed by not writing detailed enforcement rules early enough to avert widespread confusion.

"It's totally ridiculous," Carolyn L. Smith, director of the Department of Finance and Revenue, volunteered during an interview. "How can we put in a law and not have regulations to interpret it? We don't expect it will happen again. It can't. It will not!"

The regulations were not published officially until yesterday. Smith said all 15,000 retailers who file sales tax returns will be sent copies next week of the list of items that are taxable and those that are exempt from the new 8 percent tax on candy, confectionary items, chewing gum and soft drinks. Previously those items were considered food and not taxed.

Meantime, without general distribution of the rules, first-day collection of the tax was spotty and sometimes chaotic.

At the Town House Food Store, a Safeway-operated convenience outlet at 21st and L streets NW, clerks went to work an hour early yesterday hoping to memorize the rules.

But as the store filled with customers from nearby office buildings at midday, longer-than-usual lines formed as clerks shouted back and forth across five cash registers asking each other: "Do I charge on this? . . . What about this kind of juice? . . . How about these Hostess cupcakes?"

'we try to have a rule that says, 'sugar tax it -- no sugar, don't tax it.' But that doesn't work all the time." Town House checker Bobbie Blakeney said. "Like we don't tax cookies, but we do tax candies. This thing takes a Harvard lawyer to figure it out, not a stupid clerk like me."

One problem is that the District now has the most complex sales tax structure in the country, taxing items or services at five different rates, unlike most political jurisdictions around the country that tax at a single rate.

District food stores, for example, do not tax food items, except for food prepared in delicatessen departments, which is taxed at 8 percent. But they do tax such things as paper towels and detergents at 6 per cent (a rate raised yesterday from the previous 5 percent rate adopted in 1973). Now their clerks must sort out certain sweets and tax them at 8 percent.

The other D.C. sales tax rates are: 2 percent on food sold in vending machines, 10 percent on the price of hotel accommodations (which was 8 percent until yesterday) and 12 percent on the price of parking in a commercial lot or garage.

Most merchandise and bottled liquor are taxed at six percent. Restaurant meals are taxed at eight percent.

Another new sales tax that was scheduled to go into effect yesterday, 6 percent on the pump price of gasoline, was delayed for at least five days by a D.C. Superior Court judge on Thursday evening. The delay is intended to give local and federal officials time to explore issues raised by organized service station operators who oppose the tax.

At a Drugfair store at 1030 15th St. N.W. Autry Morgan, a member of the city council from Boley, Okla., watched in disbelief as clerks sorted items and scanned labels on beverage containers to see if they contained tax-free fruit juices or taxable sugared ingredients.

"These D.C. tax laws are as confusing as the federal tax laws," Morgan declared. "I think it's ridiculous."

Across the street, Vasilos Peros shrugged when a customer asked if the 30 cents paid for a roll of candy mints from his sidewalk vending cart included the new tax amounting to 2 cents.

"Tax?" Peros asked."What tax? I don't care. I'm not going to enter the tax," he said.

Although almost everything in the candy store she manages is subject to the new tax, Vetta Anderson said she was not collecting it.

Anderson, the manager of the Russell Stover store at 1039 Connecticut Ave. NW, said nobody had notified her that the D.C. City Council had enacted the new tax. "I'll wait for word from the company back home. [Stover headquarters in Kansas City], before I started charging taxes," she said. "And I have to say I sure don't think it's going to make people happy."

Doris Fine, owner of Fine Sweete Shoppe in the city-owned Eastern Market at Seventh and C streets SE, said she learned of the tax "when Joe, my accountant, called me this morning. When Joe calls, I always figure it is bad news."

Fine said she is "not raising my prices with the tax. I'm going to absorb it."

Likewise the big newsstand in the waiting room at Union Station was absorbing the cost of the tax.

Sometimes clerks were forgetful. At the Safeway at 227 Seventh St. Se, checker John Washington at first negelected to collect the tax on a two-liter bottle of ginger ale that retails at $1.49. Reminded, he held out his hand for the required 12 cents and said he thought it was his first such goof.

"It takes a few days to catch up on that stuff," his customer, Bill Fitzpatrick, said with a grin. "It's not going to happen overnight."

At the Trover Shop at 227 Pennsylvania Ave. SE, a customer asked clerk Philip Gyozd if sugarless gum was considered a taxable sweet. Gyozd didn't know, and didn't collect 2 cents on the 25-cent sale, only to find out later that all gum -- sugared or sugarless -- must be taxed.

Another Trover customer, congressional aide Phil Wallace, put a quarter on the counter to pay for his daily package of chocolate M & Ms only to be called back by clerk Ray Shaffer to pay the extra two pennies. "I thought the price went up," Wallace said as he popped a candy pellet into his mouth.

Gale Levy who with her husband operates Franklin Park Liquors at 920 14th St. NW, voiced a complaint made by numerous retailers. The new style of electronic cash registers in their stores can't handle two rates of taxation.

"This has been a nightmare," Levy said. "We couldn't get any answers from the city tax people. And my husband stayed last night to read all the labels so we would know what to tax."