What's anybody's line?

People who go to a lot of parties report that once an introduction has been negotiated, the first question asked is: ''What do you do?''

People who go to a lot of parties generally deplore this question. Europeans, they assure us, value people for who they are as people, and never ask one another at a party -- or almost anywhere else -- ''What do you do?''

Actually, our particular problem lies not with the question but with the answer. What do people do? We're not sure there is an answer any more. Once the answers came back, simple and snappy: butcher, baker, candlestick maker, banker, lawyer, Indian chief.

Now, even if one were ruthlessly determined to find out what a new acquaintance did, the inquiry would resemble a particularly murky game of 20 questions.

''What do you do?''

''I have my own little firm.''

''What does your little firm do?''

''Well, we're consultants.''

''What are you consulted on?''

''Let's put it this way. If you've got a little firm of your own, we can help you.''

A perusal of Sunday help wanted ads discloses the following jobs up for grabs , if anybody can figure out what he or she is grabbing for: ''Ambulatory collection coordinator''; ''Exercise technician''; ''Senior compensation analyst.''

L.L. Bean, that grand old Maine mail-order house, dealing in honest leather and cotton duck and all-wool plaids, ran an ad the other week for ''the newly created position of Traffic Manager.'' We aren't saying that this touch of big-city razzle-dazzle signals the beginning of the end. But we do worry that before long the Traffic Manager will be looking for a coordinator - ambulatory or not. And then what will come next? A senior compensation analyst, or worse.

Alas, fellow employees, we live in a world where ''expediting'' and ''conceptualizing'' become, not part of the job, but the job itself.

If one switches the question -- ''What do you do?'' -- from people to corporations, the answers get no clearer. In these days of the conglomerating merger, if a company is called Chewy Husks Peanut Butter, the chances are it's really into computers, hotel chains, and Arizona real estate.

Presumably, a great deal of what those people you meet at parties do is to write memos and attend conferences that try to define what their company does. More often than not they conclude: ''Information is our number one product.''

Nobody will ever do anything again, we can hear you pessimists moaning. Japanese robots will design Hong Kong robots that will produce our goods, which we will merely advertise and distribute -- a nation of Yankee pedlars, marketing wooden nutmegs made in Taiwan.

But the American doer is not necessarily doomed to vocational abstraction. Nor are the companies that the ex-doers work for inevitably destined to melt into the multinational pot.

There are signs of reversal. A few years ago RCA began to follow the fashion of diversification, which may be simplistically described as taking an interest in everybody's business but your own. The company bought out Coronet carpets, Banquet frozen foods, Gibson greeting cards, and Hertz. RCA's new chairman, Thornton Bradshaw, observing that more confusion than profit resulted from this strateGy of nomadic economics, has just announced: ''What we must do is return to our roots. Over the years we moved into other areas when we should have been concentrating on areas of our competence and building on them.''

We like that sturdy sound of a true calling. Any day now we expect to go to a party and ask, ''What do you do?'' and hear the nearest voice answer: ''I'm a distresser.'' According to the fourth edition of the ''Dictionary of Occupational Titles,'' a distresser strikes the surface of new furniture with a ''rough-edged object, such as chain, broken bottle, or rock to distress (simulate antique) furniture finish.''

Now that's really sticking to your last, as we shoemakers say.