NEVER ASK visiting relatives to make themselves at home. In Miss Manners' experience it is only when members of different branches of a family are made to feel like nervous guests in one another's homes that there is any chance of family ties surviving family visits.

The expression, "Make yourself at home," was invented for house guests who drive their hosts crazy by tracking them down at their gardening to ask, "Is it all right if I get myself a glass of water?" or sitting immobile in the living room for two hours until the hosts get up, not getting breakfast or reading the paper for fear of doing something wrong. Relatives who behave like that are trying to pick a fight.

Why, Miss Manners can hear her gentle readers musing, should people who are bound by the casual ties of blood or marriage, as well as by the sacred bonds of hospitality, be spoiling for fights? Why? Because they were allowed to start out feeling at home, and nobody took the trouble to make them feel ill at ease until it was too late.

A person can only have one home. (Miss Manners assumes that her readers are not too literal-minded to recognize that the home can encompass a town house, weekend place, country retreat, yacht and porch hammock; or it can consist of a corner of a closet or basement that has eluded parental inspection.) Within that territory, the resident is entitled to have things as he or she likes them, a style generally referred to by its designer as "right."

The major choices are: neat or mess; dirty or clean; formal or informal; and matched or eclectic, but there are infinite minute variations, from deciding whether the books should be arranged by subject or by author, down to that dreadful perennial about which way the toilet paper should unravel.

Do you begin to see the problem? A person who feels at home in a household set up by someone else is seized with an irresistible urge to set things right. This is called "helping."

It is natural to feel this way about the houses of people with whom one has previously shared a home. Parents visiting their married children are notorious offenders, but grown children visiting either their parents or adult siblings can be just as bad.

Conflicts are more common between in-laws because blood relatives have shared experience of "how things should be done." The advocates of neat and clean tend to be the oppressors, because the dirty mess proponents are generally too cowed to defend themselves. (however, Miss Manners has heard of one mother-in-law who was outraged that milk cartons were not allowed on the table of her son's household, and who attributed this quirk to the daughter-in-law's snobbishness.)

The solution to such conflict works only if practiced immediately upon the establishment of a new household. When relatives arrive, they should be treated as honored guests. The routine of the house should be explained to them, along with the rhetorical hope that it will suit their convenience. Their needs should be supplied, and offers of help accepted only for limited tasks conducted under supervision. A guest should dry dishes, for example, while a host washes, but should not be allowed to put them away. That is an invitation to rearranging the cupboards.

Any such help should be accepted with exaggerated gratitude, it being so far beyond the guest's obligations. Suggestions and advice should be met with muted sorrow. "Oh, dear, and we tried so hard to make everything look nice for you," or "Do you think so? And we were so proud of this room," or "I guess we'll never be up to your standards -- this way suits us so well and we've been happy with it."

Firmness in this approach should discourage any nesting-in, but will also establish patterns of behavior which might make it agreeable to invite these people again.

MISS MANNERS RESPONDS

Q. My recent promotion to career military officer rank has been a sobering experience, as I must now worry about all those questions of life that I heretofore have ignored with impunity. One, for example, deals with the emergence of women into society with identities of their own. Routinely tacking "and Mrs." after the husband's title is no longer appropriate. While my father could confidently address correspondence " -- and Mrs. Smith" and fill in the blank with Mr., Dr., Col., etc., I, unfortunately, must contend with an infinite number of combinations.

How does one address correspondence when the wife only, or both the husband and wife have a rank or title? Some examples that come to mind are as follows: Mr. and Dr. Smith, Dr. and Dr. Jones, LCDR and CDR Brown, CAPT and CAPT Parker. I have been assuming that the husband's title always comes first and such combinations as Dr. and Dr. Brown are preferable to Drs. Brown.

This, I feel obliged to mention, does open up a whole new area; that is, how does one deal with married couples when the wife retains her last name or hyphenates it with her husband's? There seems to be something inherently wrong with addressing a letter "Mr. Jones and Mrs. Smith." It's almost enough to make one give up writing entirely.

A. Oh, do not give up writing entirely. Miss Manners will come to your rescue. All the sobering problems of life you mention are not as lethal as the alternative to writing, the telephone, with its dreaded hold button.

The solutions you propose do not work because you need a first name to go with those titles and surnames, and what are you going to use? Mr. and Col. Betty Jo Smith?

However -- Miss Manners senses you slipping again into despair -- there is a simple solution: the two line address.

Thus you have: Col. Betty Jo Smith Mr. Lucius Smith

and CDR Loretta Brown LCDR Barry Brown

and Dr. Annabelle Jones Mr. Stanford Jones

and CAPT Georgiana Tyler-Parker CAPT George Parker

and so on. Miss Manners has put the women's names first, in these cases, because they rank higher, and also because she likes it that way. You will notice that this solution will cover any combination, from the vice admiral married to the mess steward to the hyphenated doctor married to the unhyphenated doctor. It may require more ink to write to these people than all the And Mrs. people your father knew, but don't they shound like an interesting bunch?

Q. I am planning a 70th birthday party for my husband. It is my desire to ask guests to make a charity contribution instead of a gift. Is this proper, and if so, how should the invitation be worded?

A. It must be 70 years now that Miss Manners has been telling people that there is no proper way to express your anticipation of a present, whether your object is to choose it or head it off. In your case, however, there is a particular reason for urging you merely to invite people to a party in the usual way and then tell them, either by an announcement or the appearance of a birthday cake, the nature of the occasion.

It is that most people read carelessly, will assume that this is the conventional request for a charitable contribution in lieu of flowers, and will make it with the appropriate condolences.