DEAR MISS MANNERS: How much of your yearly salary should be spent on an engagement ring?

GENTLE READER: Having been privy to a conversation among some young male economists about the cost-benefit relationship of an engagement ring (the benefit being the amount of love inspired by the size of the diamond), Miss Manners can assure you that any formula is as foolish as it is distasteful.

DEAR MISS MANNERS: Our book club selects books to read in the following way: The person whose turn it is to host suggests two or three choices, and we vote on them.

On several occasions, members have proposed, and we have selected, books by friends or acquaintances. Sometimes a member even suggests that the author attend the meeting at which we discuss the book.

This feels very awkward to me. I feel that the books should be chosen on merit alone, and that this criterion is receding into the background. Sometimes I think the member proposing the book is doing so with an eye to increasing sales. (Some of these books are self-published and are "struggling to find an audience," shall we say.)

More important, we try to have frank discussions of the books we read for this group, and frank discussion seems much less likely when the author is a friend or acquaintance. Having the author actually present for the discussion seems even more likely to inhibit our discussion.

What is your view of the matter? And how can I delicately explain my position to the group?

GENTLE READER: Suggesting to the group that you avoid authors known by members of the group, as it will inhibit the kind of free discussion that the group prizes, should be easy enough. So long as you omit the part about selecting books only on quality, Miss Manners sees no impediment to raising the issue even with an author present.

DEAR MISS MANNERS: Regarding towels to be used in a powder room -- what size towel is correct?

I have seen tiny towels the size of a washcloth, hand towels, printed paper towels and full-size bath towels. If I encounter a tiny towel and it becomes totally damp after I use it, should I tell the hostess?

My friend uses printed paper towels, but the dye often comes off on my hands. The only other towels in her powder room are very fancy and tied with a ribbon, so I assume they are not to be used at all. Help!

GENTLE READER: Oh, no, not the guest towel fetish again. Miss Manners hardly knows who is more ridiculous -- guests who refuse to touch anything except paper, or hosts who imagine that cloth towels are untouchable works of art.

She can only advise you to do the best you can, leaving the wet towel in its used state without complaint.

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: My last three lunches with different groups of friends have resulted in total discussion of food allergies and gastrointestinal issues.

It seems everyone is self-diagnosed with gluten, lactose or egg intolerances, or a variety of other issues, and they have to discuss this prior to ordering and throughout the meal. The poor wait staff need chemistry degrees to answer all the questions about the food, even after they provide special menus for these people's issues.

They also like to discuss their resulting symptoms, which are not very appetizing. Then on top of this, yesterday I was told it must be nice to be healthy as a horse, since I had been quietly listening to the discussion and made no comments on the discussion at hand.

When the dessert tray comes out, everyone agrees that you have to push the limits once in a while and order up.

I am not enjoying my friends and do not plan to continue joining them for meals. Is anyone else experiencing this new trend?

GENTLE READER: Oh, yes. It wasn't bad enough that private entertaining has been all but ruined by the difficulty of providing a menu that meets the multitude of needs -- and, more often, demands -- of guests. And also that conversation has been ruined by discussing it all.

It seems that people cannot even refrain from spoiling restaurant outings, where they can each order their own meals.

Miss Manners cannot blame you for quitting these sessions. It cannot be much fun spending time becoming acquainted with other people's digestive systems.

But if these people are good friends with otherwise redeeming qualities, perhaps you can suggest a few rules:

-- That anyone with particular requirements be in touch with the restaurant in advance to ensure that these can be met.

-- That there will be a total ban on discussing food during the meal, with the only possible exception being a spontaneous "Yum!"

DEAR MISS MANNERS: Our youngest son got married last year. I have one friend who emailed me four times asking when she is going to get a thank-you card from the newly married couple. She even asked two of our mutual friends if they received anything.

My son's wife is in school, pursuing a law degree, looking for an internship and also volunteering, and not home all day doing nothing.

I have personally thanked many people, and told them that eventually there will be an official thank-you card. Most people don't mind. They say it's the 21st century. My daughter-in-law also says she will send cards within the first year of marriage.

GENTLE READER: No, she won't. There will never be a time that she considers acknowledging other people's generosity as important as her studies, internship, volunteering, and whatever else she is doing, including resting up from all that.

But other people also have busy lives, and some of them took the time and trouble to be generous to her and your son, who could equally well write the letters. (Where is his responsibility in your complaint?) Thanks are due when presents are received -- that there is a year's leeway is an unfortunate myth.

Miss Manners warns you not to take comfort in your friends' polite assurances that they don't care. There is no 21st-century ruling that gratitude has been abolished while generosity must be continued.

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: I grew up in a foreign country, but I do not have a detectable accent when speaking English. However, most people from my country of origin have a rather distinctive accent.

What is the most polite way to respond when meeting people whose accent betrays our shared common origins and language?

On a hotel elevator on the way to my room, I struck up a bland conversation ("What a beautiful evening") in English with a couple. As they got off the elevator on a different floor than mine, I said, "Have a good evening" in our shared language.

They seemed slightly startled -- they could not have guessed I could speak their language or that I detected their slight accent -- but responded in kind.

If I am ever in doubt, of course I don't say anything. However, I think if I'm wrong, the other party would just assume I am mumbling and they didn't catch my words.

GENTLE READER: What if, like you, they think they do not have a foreign accent? What if they are suddenly panicked that you were eavesdropping on them earlier?

While Miss Manners trusts that your intentions are good, your actions feel misplaced. The consequences of guessing wrong or offending seemingly outweigh any connection that might be made -- especially as the exchange took place while the couple was leaving.

She suggests that you wait until a conversation about one's origins evolves naturally before making assumptions -- both as a practical matter and as one of diplomacy.

DEAR MISS MANNERS: I am a somewhat older gentleman who keeps in touch with about 100 people on social media. When a friend dies, I follow the customs I know -- attending the memorial service if possible, sending a condolence note and donating to a charity in the person's name.

However, I am perplexed about how to handle this occasion on social media. About a year and a half ago, a friend died. After a month, I de-friended him. I hope you will understand that I did so as a practical matter and with no ill intent.

Soon afterward, however, I ran into a mutual acquaintance who accused me of acting in haste and "abandoning" the friend. So when the next person died, I waited for almost a year before de-friending him, and there were no complaints.

Would you advise me on a respectful, appropriate period to wait before de-friending the deceased? Does it depend on how close the two of you were?

GENTLE READER: Ah, no.

But why do you need to de-friend the deceased? Not only is it redundant, it also adds insult to (extreme) injury. If the social pages of the departed remain online, it would be considerate of a close relative to take them down, so as to avoid confusion such as yours. Then Miss Manners and others will not have to ponder what the "practical matter" of declaring a literally expired friendship entails.

But she questions the motive of the busybody who accused you of abandoning your deceased friend. In cases of death, it is the bereaved who feel abandoned.

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)