IT IS appalling how few people know how to name-drop correctly. Miss Manners has seen lengthy advice given on how to introduce people to one another, much of it nonsensical, but nothing on how to drop a name gracefully.

The well-bred person does not drop names carelessly on other people's clean tablecloths. The permissible reasons are that one's social rank needs to be clarified, or one is trying, for charitable or other reasons, to stop another person fron doing it ineptly. It would be inconsiderate, for instance, for an intimate of the President's to allow a guest who innocent of this information, to tell him what Barbara Walters thinks the President thinks.

The rule of polite behavior must prevail, however. If anything, one should be particularly scrupulous when engaging in this activity.

An honest person does not drop a name he does not legitimately possess; the possibilities for getting a name wrong, or running into its best friends are too great. And a tasteful person is careful to drop less of it than he could, because one does not display all of one's wealth.

The hypothetical intimate of the President's could make a more grievous error than replying, "Well, Jimmy told me . . ."Rather, he should say, "That's interesting - I hardly ever get in to see the President anymore, so I didn't heard that."

You will notice how understated this is. You will also notice the use of the dropped name's title, rather than the first name or a nickname.

(Miss Manners observed an excellent example of this at a state dinner the President Kennedy gave early in his administration, if one may be permitted to drop an event. The less important people grabbed his arm and call him "Jack." The Attorney General, who as a sideline was the President's brother, greeted him by saying, "Good evening, Mr. President.")

You will notice, as well, how much more effective this is.

Q: Should the First Lady have gone along with the Saudi Arabian custom of women walking behind their husbands, or do you think she should have insisted have insisted on her dignity as an American woman and refused?

A: Diplomacy is a wonderful institution, which gave to humanity a choice called neither of the above . Miss Manners does not approve of anyone's going along with a custom which is derogatory; nor does Miss Manners approve of offending foreigners, especially foreigners with oil. Diplomacy has also given us the Suddern Indisposition, the Previous Engagement and the internationally recognized Travel Ailment, to say nothing of the Overpowering Need To Be Home With The Children. An accomplished diplomat recognizes the choice between Scylla and Charybdis and then reroutes the trip.

Q: Is it proper to remove one's hoes in an airplane?

A: Yes, but it is highly improper not to be able to get them on again when one has arrived at one's destination.

Q: I am heartbroken because I discovered that my husband has been receiving love letters from another woman, but he keeps changing the subject by saying I had no right to read his mail. Who is right?

A: You are quite right to seek advice from an etiquette column, rather than a psychologically oriented one. Miss Manners belives that the true value in people is not what is in their murky psyches, which many keep in as shocking a state as their bureau drawers, but in how they treat one another. You are wrong, however, in your dispute with your husband. To be deceived is the natural human condition; to read another person's mail is despicable.

Q: At a recent dinner party, I was given a soup spoon with which to eat my dessert. Can you explain that?

A: Yes, but it is impossible to explain why Americans think that teaspoons were intended for eating desserts. What you were given, correctly, is a dessert spoon. If it happens to be the same shape as spoons correctly used for consuming clear soups, that is its business.