DEAR MISS MANNERS: My friend has stated that saying “thank you” for gifts and men removing their caps in restaurants were both generational rules that are now outdated. (We are both in our 80s.)

She said we should no longer expect a thank-you for gifts, because that means the giver is giving conditionally. Her grandchildren have been advised by their mother (my friend’s daughter-in-law) that saying “thank you” for gifts is no longer necessary. Is this the trend now?

GENTLE READER: Oh, your poor friend. She is suffering from the etiquette equivalent of Stockholm syndrome.

When etiquette evolves, it is not at the direction of those who rudely violate its principles. That would be like allowing felons to revise our laws.

But as Miss Manners is the one in charge of authorizing change, she will explain to you why the examples your friend mentions are not legitimate.

Some etiquette rules have a moral basis. Gratitude, which is also an essential requirement in many religions, is permanently and inextricably linked to generosity. Those whose generosity is ignored are justified in concluding that it has not achieved its purpose of pleasing. And those who are unwilling to express gratitude should not accept favors, presents or other forms of kindness.

Other etiquette rules are merely symbolic, and therefore arbitrary and subject to change. The symbolism of hats has been in a state of confusion for some time. The traditional rule is that gentlemen remove their hats indoors as a sign of respect -- especially in a church, for example. But the arbitrariness of this is shown by the fact that piety in a synagogue is demonstrated by their wearing hats.

The traditional rule about ladies’ hats is that these did not need to be removed indoors, and wearing a head covering was even required by some churches. But then, most ladies abandoned feminine hats entirely, and many have started wearing baseball caps, which are unisex and therefore not subject to the female rule.

So in theory, the rule about gentlemen’s hats could change. But this has not yet been fully accepted. Your friend, or her masculine friends, should be aware that there are still people who are offended by seeing caps worn indoors. And while some of them are also elderly, American tourists abroad have been scorned, even by the young, for the perceived disrespect of keeping their caps on indoors, especially in churches.

DEAR MISS MANNERS: On occasion, I have given gifts to friends who then promptly mention to whom they will give my gift, or they actually give my gift to another person in my presence, immediately. I have said nothing. What, if anything, should I have done?

GENTLE READER: Cross them off your list.

When someone announces an intention to regift your offering, Miss Manners suggests putting out your hand and saying, “I didn’t mean to burden you; I’ll just take it back.” If the item is brazenly handed to someone else in your presence, you might say, “Sorry, I hadn’t thought to get you a present, but I hope you enjoy 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.)

DEAR MISS MANNERS: When I am using a one-person public restroom -- the kind with one door that locks -- often someone will try to open the door, and, finding that it is locked, will immediately follow up with knocking. Do you consider this rude?

When I am the person on the outside, and I try the door and find that it is locked, I leave the occupant in peace and wait my turn. I even feel a bit guilty for disturbing them or possibly startling them. I would never dream of further disturbing them by knocking.

I once asked a woman why she knocked after already trying the door, and she told me she was just letting me know that someone was waiting. I believe that trying the door is signal enough that someone is waiting. I interpret the additional knock as an indicator that the person is being pushy and wants me to hurry.

What do you say? Is it rude to knock?

GENTLE READER: By definition, everyone hoping to enter a restroom is in a hurry. Miss Manners would think that anyone inside should have fresh empathy for that state.

You should also understand that while rattling and knocking both make noise, they are different gestures. The rattle, a utilitarian way of determining whether the door is unlocked, is not subject to etiquette classification. A knock, in contrast, is a polite signal to the person inside that there is someone outside.

This need not deprive you of whatever time you need for the primary purpose of a restroom. But if you are in there experimenting with hairstyles, it should suggest that you yield to more pressing needs.

DEAR MISS MANNERS: My significant other and I were invited to a dinner hosted by another couple, with a third couple also in attendance. We were asked to bring dessert, so we brought a large selection of cupcakes.

My SO and I put a lot of effort into picking out flavors for each guest rather than opting for a random assortment, and we were looking forward to doling them out after dinner.

The hosts’ neighbors dropped by unexpectedly before dinner and were asked to stay. I felt slightly annoyed that our deliberate cupcake selection would be thrown off, but it hardly mattered when I realized that the host had already allowed each of his two kids to help themselves to a cupcake.

Was I justified in feeling annoyed by my dessert being distributed not as I’d thoughtfully intended, or was it considered the hosts’ right to do with it what they pleased?

GENTLE READER: Personalized cupcakes?

Miss Manners is loath to discourage thoughtfulness, personalization or cupcakes, but surely that sort of specialized effort is best made when you are the host and can control the circumstances.

Please stop feeling insulted. Once you had agreed to bring dessert, it was not your prerogative to decide when the children could eat or whether the neighbors would be welcomed.

(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 work in a fire station amongst people who, 99 percent of the time, could care less about any form of etiquette.

Due to the public’s appreciation of our services and lots of birthdays and social events, the station is a dumping ground for cake. We get at least two a week.

I know that for some reason, everyone else on the planet cuts cake working from the outside toward the inside or center. Where is the rule that states, “Thou shalt begin to consume cake from the outside edge and progressively whittle closer to the interior”?

Every time that we receive a new cake, I always try to be the first person to take a sample. I never cut out squares or pie shapes; I always carve out an oblong shape and always in the MIDDLE of the cake, thus leaving the outer perimeter intact.

Whenever I do this, my co-workers always seem perturbed and act as if the cake is ruined. Without fail, these whining hypocrites will wind up completely consuming the cake.

What’s wrong with them, or what am I missing here?! Mind you, I’m not talking about a thousand-dollar multi-tiered wedding cake. To the contrary, I’m talking about a $15 cheapo from the local grocery store, or something homemade from a person who dropped it off and will not be sharing it with us.

With all of that said, what the hell difference does it make where the chunk of cake came from?

I can’t think of any other food dish where an item is expected to be cut out in a certain way. What makes cake so special? I’m retiring in a year and would love to set this conflict to rest before I go.

GENTLE READER: How on earth do you cut a piece from the middle while keeping the rest intact? And why would you want to?

Is it really worth the effort this must take -- not to mention the resulting frosting on your sleeves -- just to prove a weirdly specific and irksome point to your co-workers? Or more likely, to play a hoax on Miss Manners?

Your co-workers are likely challenging your technique because it is leaving them with a thoroughly touched and mangled cake in your wake. In hopes of your properly enjoying your retirement, however, Miss Manners suggests that you cut a large piece of cake for yourself, big enough for you to create whatever fun shapes you want in it afterwards. Then, please, just leave the rest of it alone.

DEAR MISS MANNERS: I am wondering if it is considered polite to leave a spray can of air freshener in the guest bathroom to be used at the guest’s discretion. If so, where should the can be placed?

I’ve tried placing it on the floor near the toilet, but guests don’t seem to take the hint. What does Miss Manners suggest?

GENTLE READER: That you get better-smelling guests.

Leaving air freshener in an attractive container in plain sight is all that you can reasonably do. If the results are not to your satisfaction, Miss Manners suggests that you discreetly follow up after your guests have left.

(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.)