Chaperoning used to be one of etiquette's chief pleasures. If you are behaving so well that you're not having any fun of your own (the reasoning behind this thankless guardianship went), you can at least amuse yourself by spoiling other people's fun.

So when the job of professional third wheel was abolished, many people who prided themselves on their propriety continued to enjoy the hobby of tsk-tsking over who was seen where with whom, and wasn't it awful.

On behalf of etiquette, Miss Manners has renounced this function. If you make, or rather if you spread, assumptions that people who have the opportunity of doing you-know-what must, without further evidence, be taking advantage of that opportunity, you can no longer define yourself as proper.

It is not to condone immorality that Miss Manners has taken this sacrificial step. For that matter, she does not consent to participate in a debate about what is or is not immoral according to current fashions.

Therefore, the ruling will not affect people who are receiving criticism about their private lives because they have submitted them for social scrutiny. If you can't resist telling everyone you meet what your arrangements are, why should Miss Manners make those people resist responding?

It is, rather, to protect those who actually are minding their own business that Miss Manners is declaring that appearances do not count. What used to be considered deliciously suspicious circumstances may no longer be taken as such. Any pairs of people who are spotted dining together, who are known to have been alone in the residence of one or the other, who stay in the same hotel when traveling, or who go about town together, are going to have to be presumed to be nothing more than friends.

If this takes the fun out of running into people accidentally, she expresses her regret. But she will not relent.

Unemployed chaperons will be quick to point out that it is not only the innocent who will be protected when such a benevolent policy is practiced. And even Miss Manners admits that it is within the realm of possibility that privacy allows for some heated expressions of friendship.

But given the choice between a blanket assumption that protects some of the guilty and one that condemns or handicaps the innocent, she prefers the former. Severely to limit the locations in which ladies and gentlemen can have respectable personal or business encounters without fear of social disapproval results in either defiance of the rules, with consequent social friction, or in inhibitions that cripple normal activities.

With this decree in mind, anyone should be as able as Miss Manners to fill out a house-guest decency chart that was submitted to her by a Gentle Reader.

He asked her to check off "Proper" or "Improper" for first an adult male living alone and then an adult female living alone, in regard to entertaining one and then two visiting adult male or female relatives or friends.

With all the variables, you can imagine what an elaborate chart this makes. But crossways and sideways, there is only one answer: Oh, go ahead, invite whomever you like.

But the inquirer does not want to let Miss Manners off so easily.

"Has omission of the marital status of the guests made answering difficult?" he continues. "If so, can you please answer four times instead of two?"

Well, no. Miss Manners will give only one more answer:

If you are married, you don't want to do something that upsets your spouse. It is therefore up to you to talk him or her into the idea that what you are doing is perfectly innocent. Miss Manners has gone quite far enough in providing you with the argument.

Q. When sharing a pizza from the cardboard box it is delivered in, what should one do with the rim of the crust that is often uneaten?

Several people toss theirs back into the box, even when there is still pizza in it. This seems inappropriate and unappetizing.

What is the proper way to dispose of the crust?

A. Funny thing. The Etiquette Council seems to have neglected taking up the question of tossing uneaten pizza crusts back into a box that is also acting as a serving platter. Miss Manners is on her own.

The answer is that such crusts should be parked on extra paper napkins, to be returned to that versatile box when it is used as the garbage pail at the end of the meal. You are using napkins, aren't you?

Q. I have been informed that whistling is unladylike. While I realize that it is never polite to annoy one's neighbor, would Miss Manners be so kind as to tell me how this gender distinction came about, and whether it is still in effect? I will cease at a word from Miss Manners.

A. Then how would you get Miss Manners a taxicab when she needs one?

While it is true that whistling is unladylike most of the time, it is also true, although your informant neglected to tell you, that it is ungentlemanly at such times.

People of either gender may skip happily along a country road whistling, but neither may whistle in a bus or a theatrical dressing room.

Q. Our niece's wedding is to be a black-tie affair. Is it mandatory for the man to wear a tux? Would dark suits be a breach of etiquette for the men who hate tuxes? I am wearing a tea-length cocktail dress.

A. Etiquette makes allowances for hardship: If, for example, your husband could not afford evening clothes, no decent person would condemn him for dressing as best he could.

But to "hate tuxes" is not considered a legitimate hardship. Not by Miss Manners at any rate, and not by people who expect others to consider their weddings worth dressing up for.

Q. A certain married couple lives in a country where divorce is not an option, because of religious beliefs. The couple are legally separated. When one of the parties dies, is the surviving person considered the widow or widower?

I fear I may have been incorrect in addressing my sympathies to the children alone.

A. The legal spouse of a deceased person has indeed been widowed, but is not necessarily in need of comfort. Miss Manners trusts you know this individual situation better than she does, but she can imagine that refraining from commiserating could be the more delicate choice.