What shall I wear?" is society's second most frequently asked question. The first is, "Do you really love me?" No matter what one replies to either one, it is never accepted as settling the issue.

The only sensible answer to the clothes question is one that Miss Manners learned long ago when she was confined to a women's college dormitory, an educational experience if ever there was one. In that establishment, everyone asked. "What shall I wear?" all of the time so that, once dressed, they could go out and ask the other question.

"Wear your yellow silk, dear," a wise young women used to reply each time the question was asked. It spared her a great deal of idiotic conversation about other people's wardrobes and how they felt about each item.

However, Miss Manners is willing to discuss categories of dress.

The terms in current use are: Formal, Informal, Semiformal, Don't Dress, and Optional. None of them means anything.

Once, some of them did have meaning. Informal meant black tie, or what some people no call Formal, and Don't Dress meant dark suits, or what other people now call Formal. What Semiformal is, Miss Manners has never discovered, although it gives her a vivid picture of someone in a dinner jacket with unmatched pants. Optional is, of course, the same as saying nothing at all, but trying to make it sound organized.

You will notice that Miss Manners always explains the specifics in terms of men's clothes. This is because the difference between a woman's most formal dress and her second most formal dress is whatever she wishes to make it, while the difference between a man's is down there in black and white, even before he gets the statement from the rental agency.

For that reason, invitations that mean white tie or black tie come right out and say so. No other designations should appear on invitation cards, because they will only confuse the issue.

Ah, you say, but then, what do I wear? Miss Manners knew you were going to ask that. You have been inabove to ask that. You have been invited to a dinner that has one of the above meanlingless designations on the card, or no instructions at all, and your yellow silk is at the cleaners.

The general rule here is custom. In many communities, everyone knows that "just wear anything" means anything from the designer salon, or else anything from the floor of your closet, and "We're going to dress up" means either that we're all going to look smashing, or else we're going to comb our hair.

If you don't know, you ask. The trick is to ask a question that can be answered.

"What shall I wear?" is not such a question. Hostesses all think that it's charming to answer, "Oh, anything," and then let you turn up in jeans when everyone else is in diamonds, or the reverse. A slightly better question is, "What are YOU going to wear?" but the answer is likely to be "Oh, probably a caftan," and you won't know if it's an heirloom or a bathrobe.

Miss Manners suggests questions such as "Do you mean jeans?" or "Should Alphonso wear a tie?" or "Are long skirts being worn?" Not only do such questions yield more information, but they sound less whiney than "What shall I wear?"

MISS MANNERS RESPONDS

Q: You seem to show no sympathy for your questioners. Consider the poor woman with the prune pits. I can understand her concern, eating those prunes where everyone can see her, and not knowing the right way to remove the pits. Could you not have suggested the use of a paper napkin as a more esthetic way to hide those ugly pits?

A: A woman with a mouth full of prune pits does not need sympathy, understanding, or other forms of therapy; she needs to be told how to get those pits out of her mouth. But while we are being kindly, let us remember that the prune pit does not think of itself as unsightly, and would feel hurt at being told that it should hide in a paper napkin instead of returning, unashamed, to the plate in whatever manner, spoon or hand, it used to travel to the mouth.

Q: Our children are trained to answer the phone, "Smith residence, John speaking. "This immediately tells the caller that he has reached the correct number and to whom the caller is talking. It is then, to our way of thinking, only mannerly that the caller immediately identify himelf or herself. That the caller who has not identified himself must be asked to identify himself is a breach of manners on the part of the caller. Are we wrong in our training?

A: Only half wrong. You are confusing the duty of the caller with that of the callee.A person who wishes to be admitted to another's home, even electronically, should be expected to identify himself, but to announce one's identity first to whoever rings is unnecessary and may even be unwise.

Q: I must take issue with you on telephone etiquette. You are advising people to tell a lie by saying, "Let me see if he is in." If the calling party has any manners, they will introduce themselves before asking for their party. I will punish my children if they don't find out who is calling before they give any information at all. People who do otherwise are making it very easy for would-be robbers, rapists or other troublemakers. Remember, people calling on the phone are uninvited guests. It is not too much to ask them to identify himself before being invited in.

A: Miss Manners does not feel that politeness requires anyone to supply helpful information to criminals who are telephoning for appointments. "Let me see if he is in" suggests that one is in a busy household where people are coming and going. It is not a lie if one interprets it as the modern equivalent of a lady or gentleman's being "at home to" guests or not. One can be "in" to some people, but not to others. CAPTION: Illustration, no caption, By Charles Dana Dibson