DEAR MISS MANNERS: I believe that the rules of etiquette indicate that one should not use language that others find offensive, even if it doesn't seem so to oneself. I have just learned, for example, that "master bedroom" is offensive to some, so it should not be used.

The problem is that there doesn't seem to be anything that someone, somewhere, doesn't find offensive. Should one be ruled by the wishes of one person? If not, how does one determine what is valid? It may seem trivial, but omitting words from the vocabulary and substituting others does take some work until it becomes habitual.

GENTLE READER: Now that taking offense has become a national pastime, Miss Manners needs to distinguish between two varieties of the activity.

The first is sifting through the constant unsolicited etiquette advice from friends and family on the subject of offensive language. For that, you will have to use your own judgment, remembering that correcting another person's manners is, itself, rude.

The second is avoiding offending an actual person, as opposed to a theoretical one, and for this, the rules have not changed: Avoid commonly recognized terms of offense; know your audience; and if you see that you have, unintentionally, given offense, apologize. Anyone who does not accept a sincerely offered apology for the use of a newly minted and not-yet-generally-accepted offensive term is being rude.

DEAR MISS MANNERS: My fiancee and I are planning our wedding. She is displeased that I insist on following the rule that spouses must be invited together or not at all. Her grandmother is married to a man who has a long history of abuse against other family members; he also happens to hate me for bigoted reasons. This man is not welcome at our wedding. My fiancee wishes to invite only her grandmother, leaving the husband off of the invitation.

While I'm sympathetic, I told her we can't invite her grandmother alone, and therefore we should not invite either of them. Etiquette aside, I feel that the grandmother shares some culpability for what has happened.

My fiancee thinks I am being unreasonable, and we are at an impasse. Should I put my foot down, or should I make an exception, even though I know it is wrong?

GENTLE READER: Before you put your foot down, you should examine the ground you are standing on. Few etiquette rules are free from exceptions.

The seriousness of the accusation against the grandmother's spouse leads Miss Manners to believe that you have severed all relations with him. If that is so, it supersedes the requirement that he be invited. Grandma can come, but the offender will have to stay home.

If, instead, your use of the word was more metaphorical -- a way of saying that, while you tolerate the husband at every family event, you find his behavior disgusting -- then the rule about inviting couples reasserts itself, and you will have to choose between potentially insulting your fiancee's grandmother or once again tolerating her boorish spouse.

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: I have noticed that many establishments, from coffee shops to boutiques, are using systems that automatically ask for a tip when you are checking out -- and "helpfully" give you choices of 15%, 20% and up.

To me, tipping has always made sense for instances such as haircuts and restaurants, where the person has spent a considerable amount of time with me. For someone who took a donut out of a case and put it in a bag to receive a tip seems excessive. And I say this as someone who has worked in retail -- at a fast-food place, a home decor shop, and most recently an art gallery -- never expecting a tip for basically ringing up a sale.

I know I can hit "no tip," but then I worry the person will think I'm obnoxious and I'll feel embarrassed. What is your opinion of these systems?

GENTLE READER: That even though Miss Manners may occasionally be intimidated by all the new electronic devices in her life, she does not accept etiquette advice from them.

DEAR MISS MANNERS: Over a decade ago, I was in a relationship with a woman who made the following mealtime complaint: Immediately after having a bite of whatever dish I was enjoying (and chewing and swallowing that bite, to the very best of my memory), I would take a sip of whatever beverage I was using to "wash down" my food.

This would invariably leave a "slime trail" on the rim of the glass. The slime is uncontested and incontestable.

Isn't "sliming of the glass" a common phenomenon, and does it truly constitute a breach of etiquette? I found the entire subject amusing during my relationship with this person, but now, long after she and I have parted, it is starting to bother me that perhaps I have been committing, lifelong, some horrible etiquette faux pas.

GENTLE READER: There are many aspects of food consumption that are not pretty, and some people have stronger stomachs than others. Recognizing this, food etiquette exists so that people can share a meal without disgusting one another.

Sometimes it restrains us from doing things; other times it requires us not to notice. In this case, Miss Manners allows you to slime away so long as you refrain from sharing glasses.

DEAR MISS MANNERS: When being welcomed into the home of friends (at any time of day), I am often asked the question, "Would you like something to drink?" They provide no further information about what they have available.

It seems rude to ask what they have, and I'm generally not interested in a glass of water. I've tried, "I'll have whatever you're having," but my host may indicate that they are not having anything just now. What is the proper response? Do I decline the offer of a beverage? Ask for water?

GENTLE READER: Ask for something common -- tea, coffee -- or about a category of beverages: "Do you have any diet soda?" You may not get exactly what you want, but it is almost certain to be preferable to the Russian roulette of "I'll have what she's having."

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: As someone with limited mobility, I must often take cabs. I once found myself in a taxi, for an hour-long ride, with a driver who read "alternative" news sites, believed in conspiracy theories and apparently wanted to talk about them. I'm not sure how the conversation began, nor could I determine the best way to bring it to a close.

After approximately 15 minutes of this one-sided exchange, I blurted out, "Can we not talk about this? I find it very upsetting." The driver apologized and the rest of the ride was uneventful.

I'd like to know if there is a gentler way to end these types of conversations -- both for etiquette's sake, and to avoid upsetting someone enough to be left on the side of the road.

GENTLE READER: Time was when taxi drivers' political talk was considered a significant indication of public opinion. Reams about the state of the nation were written by pundits based on conversations during their transportation to the office.

How enlightening that was, Miss Manners cannot presume to say. But the toxic state of current political discourse makes the casual airing of opinions among strangers unappealing, if not dangerous.

Even stating why you find this upsetting could open a debate. All you need to say is, "I'm afraid I need some quiet time."

DEAR MISS MANNERS: The woman ahead of me in line left her overflowing grocery cart to take her toddler to the bathroom. When the line moved forward, I stepped around her cart and put my (few) items on the conveyor.

She came back before I finished checking out and proceeded to shame me in a loud voice for "cutting in line." To my chagrin, another young matron, also with an overflowing cart and a toddler in tow, was bagging her items ahead of me and chimed in.

Caught in the crossfire, I was at a loss for words (and so was the cashier). I completed my transaction and left, but I wish I had had the presence of mind to explain that since she left, no, I did not cut in front of her.

I feel the rules of etiquette have been turned upside down. I think I did the right thing in not saying anything, as it would have made things worse. I felt terrible and spent the day depressed and wondering if this was a harbinger of things to come.

GENTLE READER: Oh, not again -- another grocery line fight!

Miss Manners has gotten dozens of these lately. Aren't people advised to eat before they shop, so they won't overbuy? Maybe if they weren't hungry, they wouldn't be quite so growly.

Leaving is the best solution to such public rudeness. But if you had to stay to retrieve your groceries, you could have said, "I didn't know how long you would be away, and I didn't want to hold up the line."

DEAR MISS MANNERS: When meeting other people at a restaurant, often the host asks the first to arrive if they wish to be seated or to wait for the rest of the party to arrive. Is it proper to be seated ahead of the others? If so, is it proper to order drinks or appetizers while waiting?

GENTLE READER: Only if they are really late, and you greet them by saying, "I know you wouldn't have wanted us to wait."

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)