Capt. Charles Boycott was a 19th-century English land agent in Ireland. Like most men in his chosen field, he did not suffer from an enlarged heart. Boycott's ruthless refusal to negotiate the rents of his impoverished Irish tenants led first to his being ostracized and later to his becoming a verb. That's why what I'm now considering organizing would be called a boycott.

The boycott would be directed at a small sub-species of a great American business and art form: the automobile bumper sticker. I not only read bumper stickers; I like them. In the continuing saga of determining the national mood, bumper stickers can be and frequently are vital signs.

Right now, the traditional political bumper sticker is scarce. In its place is the radio station bumper sticker, which tells the format -- talk, rock, country and/or FM -- and the dial location of the station being endorsed.The radio sticker is relatively recent, and it is popular.

The political bumper sticker is not much more popular than politics. This year, an ancient phenomenon repeated itself. Just like the swallows returning to Capistrano on March 19, the winning presidential candidate's bumper sticker in 1980 turned out to have stronger "stickum" than the loser's sticker. It is truly remarkable. Reagan defeated Carter by about 5 to 4 in the popular vote, but his present margin, in bumpers, is closer to 20 to 1. In fact, the Anderson stickers stuck a lot better than the Carter stickers did.

Astrological signs are also something relatively new in American statement-making bumper stickers, as in the Capricorn in the Thunderbird.

Before the indictment is made, let me present some of my credentials: veteran of several hundred towel fights in locker rooms; graduate work completed at Parris Island Marine recruit depot; able to name the entire starting lineup of the 1950 Philadelphia Phillies. In short, I am not now nor have I ever been a prude.

But I am today organizing a boycott of people who produce and people who promote tacky and tasteless bumper stickers. Most of them talk a lot about it . This is not to be confused with the it of religious discovery or witness. That's perfectly OK with me. wNor does it have anything to do with the "America -- Love It or Leave It" sticker that was big a few seasons ago.

No, this it is lower-case and no-class. The bumper stickers report in unsubtle detail how often, with whom and how expertly different occupations -- teachers, scuba divers, nurses -- do it . Such bumper stickers are tasteless and dumb and offensive.

The tasteless and the offensive and the dumb have not been quarantined. T-shirts and even print advertising have picked up the it virus. Semi-respectable publications, forever anxious about being seen as stodgy by the emerging generation, will do almost anything to prove that they're with it . Their approach is to use the word to indicate how frequently they publish, as in: you can get it "every morning," or get it monthly." Get it? Pretty sad.

But the bumper-sticker users of such printed garbage have become the automotive equivalent of the raincoat flasher's imposing his grossness upon all. That all, of course, includes the young, the newly literate. But the tasteless do not concern themselves with such matters.

What all of these offensive bumper stickers and T-shirts have become for me is an invasion of my privacy -- similar to that imposed by the compulsively candid casual acquaintance who has to tell in embarrassingly graphic detail the very intimate problems being experienced by a mate. That, too, is an invasion of privacy -- mine and the mate's.

Whenever I see another one of those bumper stickers, I think: somebody should tell the driver, and the driver's parents if necessary. Well, I have just appointed myself that somebody. It is offensive, tasteless and dumb. Why don't you do everyone else a favor and give it a rest?