BUSINESS entertaining is rather a curious term, Miss Manners always thought. What is amusing, pray, about having to work overtime and to pretend that it is just the same as having a real social life with real friends?

Nor is she convinced that it makes the business world go around any faster. Miss Manners spent years of her life attending diplomatic parties, for reasons she has forgotten, and the only useful result she could see was to maintain modest citizens, such as Miss Manners herself and members of the international diplomatic community, in a style of 19th-century lavishness that even few of the rich can now afford.

That is a worthy cause, of course. If it were not for expense accounts of one kind or another, we would all have to live within our means and what would become of the champagne industry? But the common justifications -- that business entertaining generates good will, makes informal exchanges possible and is necessary to keep up with one's rivals -- merely mean that one must do it because it is done. IT SEEMS TO miss Manners that any sensible business can be conducted directly, that good will does not protect bad business, and people can as easily come to blunder as to ingratiate themselves in pseudo-social circumstances.

Having said that, Miss Manners will now turn her attention conscientiously to the business of business entertainments.

Lunch in a restaurant is by far the best way to do this, as many people resent carrying business over into hours usually devoted to families, friends, or sitting in a hot bath with a good book.

There is no excuse for being late to a business luncheon, short of having been run over on the way there. Everyone is "busy" and "rushed" in the middle of the day. The person who proposed the luncheon insists upon picking up the check; gender is not a factor, and any suggestion that it is should be cheerfully ignored.

For business dinners -- unless they are held among people who are going back to work afterwards, in which case they are treated as lunches -- it is customary to invite the spouses or their equivalents, as an acknowledgement that the event will be occupying private time. If these people have any sense, they won't go, anyway.

large scale business luncheon or dinner parties will succeed in the proportion that they imitate real social events. Correct invitations, a prominent guest of honor or important occasion as an excuse, good food and drink and a decent amount of general conversation help to lull people into thinking that they are there because they want to be, not because they have to be for the sake of their careers.

The business cocktail party is a bastardization of an already unnatural form (or rather, natural, if one is to stay with the metaphor). People are at their most greedy and ungrateful when appraising cocktail parties, even when the hosts are friends. So the best chance for a business to impress them is to entertain on a scale not usually available to to the guests -- the food, the drink, the place where it is held. After all, this is, as Miss Manners said, the real attraction of organization-sponsored entertainment.

Anyone who attempted to have fun in the usual social way -- overeating, overdrinking, heavy flirting -- would be jeopardizing his or her career.

So enjoy these occasions, but just don't have a good time. That is what friends are for. MISS MANNERS RESPONDS

Q. When you talk about proper stationery, I think you are putting your readers to an unnecessary, and sometimes actually counter-productive, expense.My law firm, for example, has beautiful letterhead paper, properly engraved in a way of which even you would approve. I find it does for almost all my needs; that, in fact, people pay more attention to such letters than they would to the complaints, for example of an ordinary person on paper with just a name or street address.

Hotels also provide impressive stationery, and using that -- good hotels give you a generous supply you can take home with you -- is beneficial to them, because of the advertising, as well as to the person who saves himself needless bother and expense. Why don't you advise your readers on this?

A. Oh, that's not necessary. You should see Miss Manners' mail. At first glance, you would think that she is continually carrying on important legal business or being thought of by people in the midst of the most luxurious trips. The misappropriation of writing paper to give a false impression has caught on very well, without any help from Miss Manners.

She thoroughly disapproves of the practice. Using your professional letterhead paper to conduct personal business suggests, fraudulently, that the full weight of your emloyer is behind your every private transaction. When you try to create the impression that the ire of your law firm will be felt if the vacuum cleaner part you ordered is not delivered soon, any simpleton can see that it is a bluff.

As for hotel paper, Miss Manners believes that it, like the soap, towels and bedspreads, was meant to be used in transit by people who do not have their own such articles with them. A person who writes from his home town on paper from a distant hotel gives the recipient a vivid picture of his thriftily packing away in his suitcase whatever he thinks he can carry out of the hotel without being arrested.

Miss Manners' favorite vision, however, is created by a woman who has been for years using the paper of a famous ocean liner on which she once traveled. The ship is no longer in service, and when Miss Manners sees its name on a letter, she has a charming picture of the writer diligently keeping up her correspondence from the bottom of the sea.

Q. My son is being married out of state. The bride's mother is having a lovely reception. She asked me not to invite more than 80 guests, as she will be inviting 80 also.

My husband and I have many friends and business acquaintances who should be invited. We therefore plan to have a large post-honeymoon reception, inviting 200 guests, including the parents and family of the bride.

Now, can you advise me about the invitations? Do we invite these people separately, or would it be proper to enclose an invitation along with the formal wedding invitation? Do we print announcements of the wedding and enclose our party invitation? I want to do the proper thing, but it is physically impossible to invite the large number of friends, relatives, etc., to the out-of-town wedding.

A. Indeed, a delayed reception such as you propose, is the correct and gracious solution to the bride's family's space limitation problem. But you must be careful not to seem to be passing this off as part of the original wedding festivities; it is, instead a charming but different tradition, namely a reception in honor of the newly married couple.

Therefore, your invitations should not be sent with the wedding invitations or with the wedding announcements, both of which are issued by the bride's parents. For a reception such as you describe, the form is: In honor of Mr. and Mrs. Franklin Adorable (or less formally, "Daisy and Franklin") Mr. and Mrs. August Proper request the honor of your company on Saturday, the eighth of May at eight o'clock The Decade Club (or 1117 Rotten Row)