DEAR MISS MANNERS: What is the protocol for addressing a U.S. citizen by a title they obtained through marriage, e.g., “countess” or “princess”?

A newspaper book reviewer referred to Lee Radziwill as “princess.” In another article, a reality television “star” refers to herself as “countess.” Both women are American.

Is it correct for Americans to use such titles? I always thought that Americans should not -- that, in the words of a dear, late friend, “It’s just not done.”

GENTLE READER: Yes, but so many things that are just not done are done.

Those who retain their American citizenship should not use titles in reference to themselves. For that matter, no titled people, domestic or foreign, should ever refer to themselves by using their own titles. This is such an established tradition among aristocrats that anyone who violates it is under suspicion of using a false title.

But one of your examples is the opposite: namely, how other Americans should address or refer to those with titles. Miss Manners sees several factors at play here: courtesy, practicality and silliness.

Addressing people as they wish to be addressed is a matter of courtesy.

The practical part is so that we know which Elizabeth you are talking about.

Those reasons alone would justify using the titles by which these celebrities are known.

As for the silliness: Many Americans are frightfully fond of titles, and toss them around haphazardly. It was impossible to convince such people that there was no “Princess Diana.” She was styled Lady Diana because of her birth -- itself a courtesy title, because the British recognize only one title holder in a family -- and, by marriage, Diana, Princess of Wales.

The error that Miss Manners sees is not in addressing others by their titles but in doing so incorrectly.

DEAR MISS MANNERS: My husband and I were invited to a wedding in which the bride and groom had set up a charity registry. I was very glad to see information on the three charities designated for wedding tributes highlighted on the couple’s website, since this was our first experience with this type of event.

While I’m certainly not “Miss Manners,” I was somewhat surprised that the charity registry was mentioned again on the formal wedding invitation. As we drove in rush-hour traffic from the airport to the hotel on wedding weekend, we each received emails from the bride and groom. (Other wedding guests we know received the identical email.) The message was a reminder to arrive on time for the ceremony and to “please keep in mind that we have established a charity registry for this event, designating gifts to three charities that are near and dear to our hearts. Please give generously.”

What’s your thought on all of this? By the way, nearly one year has passed and most of the guests at this event have yet to receive thank-you notes from the bride and groom.

GENTLE READER: That is because they are busy thanking themselves for being so generous and charitable, using your money. Miss Manners has always thought it odd that those who pride themselves on being virtuous at others’ expense so often fail to practice the virtue of gratitude.

(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: My roommate clips his fingernails into the sink and washes the cuttings down the drain. I’ve asked dozens of people over the years, and not a single one has expressed anything less than disgust. Another factor is that it clogs the sink drain, which he takes care of ... eventually.

Now, this is a good friend of mine, and we generally get along really well as roommates. He doesn’t handle confrontation very well, though, and is often resistant to change. So I’ve swallowed it; he doesn’t need the stress over something that really is a minor issue. No big deal.

But it’s still a little ping of irritation in the bathroom once in a while. It just seems so gross and weird to me (and everyone else, apparently). I’m not sure I’m looking for solution, but I’d be interested in your thoughts on the matter.

GENTLE READER: All sorts of disgusting things go down the drain. That is what it is for. Miss Manners does not advise you to get into an argument about the relative disgusting-ness of everything down there.

But surely you must want a solution. Small irritations, repeated often enough, lead to the breakup of civility, if not of households.

And you have two grounds of argument against your roommate’s practice. One is the danger of these clippings clogging the sink. Not being a plumber, Miss Manners is not certain of this possibility.

But there is no doubt that you are annoyed. The outlook is not bright for people who live together in a state of annoyance. This should be the sole grounds on which you appeal to him to stop. Not that it’s “gross and weird,” nor even that when sufficiently provoked, you might turn violent.

DEAR MISS MANNERS: My next-door neighbor’s daughter died at just 16 years old. My family and I feel so bad, but what do you say to someone when they are experiencing a child’s death?

I don’t like doing what other people do, as I would like it to be sentimental. Do you have any ideas and what is the appropriate etiquette during a turbulent time like this?

GENTLE READER: Of course you want to be sentimental, in the sense of showing genuine sentiments (as opposed to the exaggerated quality the word often implies). And you don’t want to reel off the mechanical “thoughts and prayers” response that has become so automatic.

Yet the ways to express genuine compassion to the bereaved are conventional. You want them to know that you feel for them, and the greatest comfort is to speak to them of the importance of the person they have lost. Miss Manners cautions you not to be afraid of doing this in the customary ways: letters, visits, flowers, food. Do not try to guess or predict their feelings or offer false comfort. People say such hurtful things -- typically “I know how you feel,” “You’ll have other children” or “It’s time for you to pull yourself together” -- when they try to be original.

(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’m a woman who has done a fair amount of online dating, on a few different sites. After messaging back and forth, arrangements are generally made to have a phone call, assuming both are interested.

I always review the man’s profile before the call, because it may have been several days or longer since I read it. It seems like the polite and prudent thing to do. That way I can mention things that he said, and ask about his job or places he’s traveled.

However, in some cases, I can tell that the man has not done the same, because he is asking me very basic stuff that is in my profile. I don’t expect him to memorize everything or know everything, but doing a little homework shows the other person some respect.

Is there a polite way for me to comment on this? I’m afraid it would sound snarky if I said, “Did you even read my profile?” Or, “Well, Joe, all that information is in my profile.”

GENTLE READER: “As I mentioned in my profile -- sorry if I am repeating myself -- I do love fly fishing and the changing autumn leaves. I think you said in yours that you preferred cheese-rolling on grassy hills?”

DEAR MISS MANNERS: I asked my recently widowed neighbor and friend if she would like to come over for a drink. She inquired about the time, and I told her, “about 5 p.m., or whenever you get here.”

She arrived at 5:12 p.m. with some sushi she had purchased. I made her drink of choice and we chatted while we snacked. There was no mention of dinner during our happy hour.

About 6 p.m., I turned on my stove to start cooking. My neighbor asked what I was preparing. I told her, and she finished her drink. That is when she asked my wife, “Will we be eating here or in the dining room?”

Caught off-guard, I did not know what to say. Neither did my wife. But after a moment or two of raised eyebrows my wife said, “In the dining room.”

While I was deboning the chicken breasts, our neighbor came over and grabbed one of the bones from the breast and started chewing on it. We are still speechless. How should we have handled this?

GENTLE READER: “5 p.m. or whenever you get here” is a difficult drinks-only time to maintain when you eat dinner at 6 p.m. As clear as you believe you made your invitation, the timing of it right before a meal was confusing, particularly as you went ahead and prepared it right in front of your guest.

True, there is no excuse for her to gnaw at food uninvited -- even domesticated animals are roundly reprimanded for that -- but as with animals, food that is enticingly laid out in front of them seems logically intended for their consumption.

Miss Manners recommends that you do your level best to regain your speech and set an earlier time for a drinks-only hour next time. And refrain from making dinner in front of guests with whom you don’t plan on enjoying it.

(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.)