DEAR MISS MANNERS: I recollect that you cited only two occasions on which you can wear tiaras -- the opera and visiting with royalty.

Lately the subject has arisen in connection with a guest wearing her tiara to a wedding. Can you enlighten me on this pressing issue?

GENTLE READER: In theory, Miss Manners is all for the return of the tiara. Traditionally, ladies always "dressed" their hair, with jewels or flowers -- hence the surviving term "hairdressing."

So she will overcome her resistance to seeming flexible and add that she is amused and even mildly charmed by ladies who top off evening clothes with those lovely objects that have been neglected for decades. Indeed, she will add that some tiaras can be adapted to be worn below a chignon, to the side of a French twist, or as necklaces.

But even royalty doesn't wear tiaras on all occasions. Never to brunch, for example. And noblesse oblige requires not wearing a headdress that might seem to mimic that of the chief figure. So one may wear a tiara in the presence of a queen, but not an actual crown; and not a tiara in the presence of a bride who might use one to secure her veil.

DEAR MISS MANNERS: I am a uniformed security officer in a high-rise office building lobby. Part of my job is to greet tenants and visitors with, "Hello, how are you today?" or "Have a nice day." At night, I say, "Good night. Drive safe," or a similarly upbeat greeting. I am a people person and love this part of my job.

Am I being rude or intrusive if the people are talking on cellphones or reading texted messages? My boss wants all lobby patrons to know that a security officer is present, and greeting folks is what she told me to do.

GENTLE READER: As a security guard, you are undoubtedly called upon to exercise discretion. Miss Manners supposes that you must be constantly judging whom you need to keep watching and who legitimately belongs there.

Your greetings need not be standardized, either. Some people will welcome a spoken greeting, some may be acknowledged merely with a pleasant nod, and some may notice your presence only when you step forward to usher them out. Your boss asked you to greet people, not to annoy them.

DEAR MISS MANNERS: I have a shower invitation to send out, and it states cocktails and light fare. But we are having nonalcoholic beverages and finger foods (hors d'oeuvres). What is the best way to word it so everyone understands?

GENTLE READER: Call them crazy, but everyone thinks that an invitation to cocktails involves -- well, cocktails. And "light fare" is what Miss Manners seeks in an airplane ticket, and she is not referring to the pretzels.

What you are giving sounds like a tea. That is what the invitation should state. And while the same truth-in-advertising rule still applies, tea need not be the only nonalcoholic drink that you serve.

(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: A lot of my friends are starting to have kids, and whereas their first priority is definitely taking care of their children, they still make time to hang out, which is really touching.

However, when I pick them up, a lot of times they prefer to sit in the back seat next to the car seat of their (usually sleeping) child instead of up front with me. This makes me feel like their cab driver instead of a friend hanging out with them.

Is this something I should be "sucking up" and going with, or would it be OK for me to communicate this to them? And if this is something I should be communicating to them, how do I approach it?

GENTLE READER: Convincing new parents that their babies will be fine without them is a fruitless task.

But with any luck, this is a short-term problem. Miss Manners is confident that most of these parents will soon outgrow this phase and want to sit up front for some adult conversation.

Until then, however, you are probably better off being annoyed by being alone in front, than by elbows -- or worse -- in your face while driving. No doubt the offending parent would be constantly reaching back to check on the child, give out bottles, and retrieve toys in the hilarious game of "Uh-oh! It dropped."

In the meantime, however, if you want to get benevolent revenge, next time the parent is driving, you can ask to sit in the back with the child to "keep her company." The parent will either be ecstatic at your enthusiasm for the child, or your point will be driven home. Literally.

DEAR MISS MANNERS: I was at a friend's house and noticed a piece of thread and a hair on my black pants.

What should I do? Pick it off and drop it on my friend's carpeting? Or just leave it there till I get home?

GENTLE READER: Is there no garbage receptacle? This would be Miss Manners' first choice for disposal of the hair and thread. If not, to whom do they belong?

Regardless, a show should not be made of their disposal. But if there is no obvious place for discarding them and you believe them to belong to your friend, Miss Manners will allow you to discreetly return them to their assumed origin.

DEAR MISS MANNERS: When is the appropriate time frame after a proposal to throw an engagement party?

GENTLE READER: An increasing number of gentlemen seem to think that the proposal itself should be a surprise party and make it as public as possible, rather than a private moment for the couple.

That nullifies the traditional intent of the engagement party, which is to announce an engagement. (Yes, really -- no matter how many people believe its purpose is to open a fund-raising season.)

But Miss Manners has long since lost that battle, with every step of the courtship now posted on social media. She would at least request that it be held closer to the proposal than to the wedding.

(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: Is it OK to spoon out the remains of the froth from a cappuccino coffee?

GENTLE READER: Foods that cling to the tableware are always a challenge, particularly as they tend to be the tastiest bits. Miss Manners has no objection to your dislodging the clinging froth, so long as no inadvertent spectators are injured.

DEAR MISS MANNERS: Sometimes, when at a loss as to what to get someone, I opt for a gift card. A while later, I have pleasantly asked what they got with it.

Oh my goodness, you'd think I'd rudely asked them if they were wearing any underwear! And they won't say or can't remember. Not just one time, but every time -- the teenagers are the worst.

So I adapted, and at the giving time I have sweetly asked (with brief eye contact) to please let me know what I "got" them.

Oh yes, they certainly will. Happiness and smiles all around. But then they don't. Is it wrong to ask what someone got with their gift card? My current solution has been to tell them I will be giving them a gift card and ask where would they would like to use it.

GENTLE READER: The reason Miss Manners dislikes gift cards is that they show a lack of knowledge or effort -- or both -- on the part of the gift giver.

So it does not seem fair that, having not yourself made the effort to determine what the recipient would like, you should also burden them with having to report back the results. The simplest way to know what you give people is to give it to them.

DEAR MISS MANNERS: When friends invite me over for dinner, sometimes the meat they have lovingly prepared is served with large amounts of fat. I have always trimmed it off and set it neatly to one side as I would bones, and no one has ever said anything.

Still, I have begun to worry that this may imply a criticism of their meal. I have been unable to determine if they eat or don't eat it.

GENTLE READER: Presumably it is easy enough to see if your hosts eat the fat on their own plates, and Miss Manners does not inquire what happens to food on your plate after it is removed from the table. If the dog is enjoying the bones, she has no objection.

You are entitled to eat -- or not eat -- what you wish, so long as you do not attempt to explain it. And if no one is complaining, your concern appears to be unwarranted.

DEAR MISS MANNERS: My brother-in-law corrects me when I don't say "please" to my husband. What I say is, "Will you get me some coffee?" That is asking, not demanding.

I am 62, and my brother-in-law is 60. This is crazy!

GENTLE READER: Crazy, in Miss Manners' opinion, is eschewing polite forms with someone with whom one lives. And, for that matter, attempting to teach manners to one's stubborn sister-in-law.

(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.)