WASHINGTONIANS might want to take a few precautions in the next couple of weeks, in anticipation of Hogate's 50th anniversary celebration.

Among the anniversary events -- which started on January 2 and are threatening to continue throughout the year -- is the creation of the World's Biggest Rum Bun by Hogate chefs, for Valentine's Day. Even the normal rum buns, Hogate's signature item since its beginning, have been a little daunting and sticky with confectioners' sugar frosting. I can imagine that dealing with a giant rum bun might involve something akin to a sugary version of mud wrestling.

MAYBE THEY THINK IT GROWS ON McCORMICK BUSHES -- The main dishes at Mrs. K's Toll House are garnished with a hefty fluff of fresh parsley sprigs, but on the same plates the meats and seafoods are likely to be garnished with a sprinkle of dried parsley. Surely somebody knows that the fresh stuff can actually be chopped.

Well, maybe not, since nobody seems to know either that crab meat can be picked free of bits of shell. When a diner asked one waitress which was the best main dish, she suggested the crab imperial, "if it doesn't have a lot of shell; but you never can tell."

FROM THE CAVIAR PATROL -- Supposedly all the leftover caviar has been swept from the corners of the old Iranian embassy, but the place, now called the State Department Annex, is being put to appropriate use once more. It is to be the site of the National Kidney Foundation's annual Valentine Champagne Gala on February 13. And the theme will, obviously enough, be "A Persian Fantasy." Given that, and the $100 per person price, maybe you'd want to plan for caviar after all. For reservations call 337-6600.

SMOKESCREEN IN ARLINGTON -- A non-smoker with a complaint has raised an interesting question: In a restaurant with several small rooms, could one table in a room of four be designated as non-smoking and the restaurant still be in compliance with the law of 25 percent non-smoking tables? A check of Arlington County regulations showed nothing to specifically forbid that arrangement; the regulations merely require that at least 25 percent of a restaurant be reserved for non-smokers. Gordon Christensen, Arlington County Sanitarian Supervisor, said, though, simply designating one table out of four would contradict the spirit of the law. What inspectors look for in restaurants is a designated non-smoking area that is physically separated -- by partitions, plants or the like -- from smoking areas. He added that while Arlington's regulations, like those in most jurisdictions, require only 25 percent of a restaurant to be designated non-smoking, most restaurants are finding it necessary to provide even more non-smoking space, some as much as 40 percent of the tables.