The nearly ideal Wedding Guest is the one who has just been rimed at by the Ancient Mariner. True, he doesn't make it to the wedding feast, being so depressed after 142 verses that he decides to go home to bed, instead. That is not good, especially since the caterer has already charged for what he was expected to eat.

But short of being overcome by the woes of the world, a frame of mind that is gently philosophical is the best for attending a wedding. It is in the context of life's troubles and tragedies that the love and faith of two people pledging themselves to each other is sweetest. The best wedding guest is the one who cannot suppress a tear.

Why, then, are there so many who cannot suppress a sneer?

Miss Manners does not attribute this outrageous behavior to the unnatural feelings of those who serve as wedding guests. The wedding guests, after all, are the natural well-wishers of the bridal couple, and were specifically chosen by them.

(Just a minute. Someone has a question. Yes? You there, in the fingertip veil. You say that you didn't choose your Aunt Bernice, or your half sister's second husband, much less his teen-aged son by his first marriage, but you had to have them, anyway? A mere technicality, my dear. Someone in your family chose them, and then someone put them on the list. Miss Manners certainly didn't choose them.)

In Miss Manners' opinion, it is the attitudes demonstrated by the principals of most weddings, and the values these seem to indicate, that turn their loved ones into their harshest critics. When the guests are cynical, it is because their hosts have first become so.

The wedding guests, being relatives and friends, are in a position to know the general financial level of the family, and the ordinary social style they practice. If the wedding is markedly above either--not just a heightened and festive version, but a show from a far grander world, obviously straining resources--the guests will snicker. They will know that it is done to impress them, or to fulfill a grandiose daydream that might better have remained private, and they will refuse to be carried away with the romance of it all as they busily reckon up the bills.

Worse, they may have gotten wind of certain monetary reckonings with the bridal families.

Are these people auctioning off family authority, yielding symbolic roles and authority for making social decisions, on the basis of who pays the bills? Are they figuring in the wedding presents as a return on their investment in the wedding and attempting to manipulate this potential as it will best serve them, instead of pretending surprise at the generosity of their friends? Are they selecting who among these friends will be invited to the wedding by calculating how many people they can have at so much per head, rather than putting down all the people they wanted to share the occasion and alloting their funds among them?

Such commercialization shows, and it spreads a calculating attitude among the wedding guests. To encourage wedding guests to find the occasion romantic and moving, the participants must first do so, too.

Or they could plant an elderly uncle on the sidewalk, to prepare the wedding guests with a tale of his fishing and guilt trip. MISS MANNERS RESPONDS

Q. How do you know when and what kind of wine to serve? I lived a very sheltered life as a child and, when I was married, I entertained very little and never served drinks. I feel socially backward. I'd like to have poise and confidence, so I'd feel at ease having people visit my apartment. It's important for my 13-year-old daughter, also. She feels cheated.

I also feel ill at ease about tipping, and who follows whom, and where to sit in a nice restaurant. Do you tip for a cup of coffee at a moderate-price restaurant? Is 20 cents for each dollar spent average for tipping--even the taxi and the paper boy? I feel so ignorant and I'm middle-aged.

A. If Miss Manners fulfills the obligations of her profession by answering each of your questions, will you keep it a secret if she then momentarily violates the code of etiquette by offering you a bit of extra comfort?

The basic rule of wine is: red with meat, white with poultry and fish, and sweet wines with desserts only. Do not attempt anything more complicated, and do not buy anything you cannot easily afford. The lady follows the hostess or captain in a restaurant, but the gentleman leads if the patrons are fending for themselves. An average tip is 15 percent; 20 percent is a good tip. The exception is that one does not leave less than a quarter, even if that is a huge percent of the bill, as it would be if you only ordered coffee.

And now for the secret comfort: Ignorance of such matters, far from being disgraceful, can even be rather charming. Everybody drinks vin ordinaire (oh, yes they do), but if you want something special, your wine merchant will be pleased to be consulted, and a discriminating guest would be wildly flattered to be asked for advice.

Q. Please help me resolve a matter that has caused me considerable anguish since my wedding day, 10 months ago.

On that otherwise glorious day, a number of our wedding gifts were taken after the reception. These presents were brought to the club, and were being transported home by members of our family when thieves broke into the car and disappeared into the night.

The gifts were, of course, unopened, so we have no way of knowing who sent them.

This seemingly irresolvable probem has haunted me every day of our otherwise blissfully happy marriage. At last, I am seeking your professional help. The thought of facing another year with this lurking shadow is more than I can bear.

A. Does it help that Miss Manners now feels haunted, too? As dear Nathanael West so vividly showed in his "Miss Lonelyhearts," it is the ultimate fear of every advice columnist to be confronted with the anguish of an obviously worthy person with an admittedly irresolvable problem.

You are right that you cannot confront guests who may not have given you presents with apologies for what was lost. And yet how can you go on living with this shadow across your blameless life?

Frantically hoping to help, Miss Manners can only think of getting the story around, so that the right people, hearing of your troubles, may come forward and identify themselves. You, too, should get the story around by fashioning it into an anecdote and telling it whenever you get the chance--at parties, in letters, on Christmas cards. Perhaps you could work telling it into a charming little party for the suspected wedding guests on the occasion of your anniversary.

Beyond that, Miss Manners can only resort to the small comfort of using the tragedy as an example to others, in the hope of preventing its happening again. How many times has she asked wedding guests to refrain from bringing their presents to the wedding? Up until now, she did so only to point out the inconvenience to the bridal couple of making gracious acceptances, much less opening and storing, presents while they are meeting their other social obligations at the wedding reception.

But this shows us the full extent of what can go wrong when you violate the sacred laws of etiquette. Is the suffering of an innocent bride really worth it?