DEAR MISS MANNERS: Is it rude to announce that today is your birthday, either in person or on social media? I’ve always thought people jubilantly declaring “It’s my birthday!” were just begging for birthday wishes or gifts. It seems tasteless. What are your thoughts?

GENTLE READER: That yes, after a certain age -- say, 12 -- one does not enter a room, or the social media equivalent, by announcing one’s own birthday.

If, however, it can be coyly and casually folded into the conversation -- for example, as the answer to “How are you?” -- Miss Manners would not fault your enthusiasm.

DEAR MISS MANNERS: We have three cats. When we have guests for the first time, I try to remember to mention we have cats since some people are allergic, while others just don’t like them. However, sometimes I don’t think about it when extending an invitation.

Whose responsibility is it to raise the issue: the host’s or the guest’s? If someone has a food allergy and is coming for dinner, I assume they will let me know. Is it the same for pets?

GENTLE READER: No. And, Miss Manners notes, it is not the case for food allergies, either, unless it is something life-threateningly severe. Guests should not be vetting their hosts for all allergen possibilities and making guesses at both what is being served and who will be present. And they should definitely not be voicing and listing all of their mere dislikes and preferences, even if asked.

It is, however, generally polite that a host inquire about allergies before preparing a meal, and inform guests of any allergy-producing pets. If, as in your case, you forget, let them know when you remember -- or as they come through the door -- and do everything reasonable to isolate or eliminate the offenders. It should be noted, however, that this rule does not apply to any equally offensive humans.

DEAR MISS MANNERS: We often meet friends at restaurants. If one party arrives ahead of the other, should they go to the table or wait for the other party to arrive so they can all be seated at the same time?

I would like to wait for them, but one couple always seems to arrive before us and they go to the table without us, even if I have made the reservation. Should I care, or not?

GENTLE READER: Not. Restaurant rules differ from dinner parties at one’s home. At the latter, guests wait to be seated until their hosts indicate that it is time to do so, and are seated themselves.

Miss Manners is surprised, however, that the situation you described has been an issue at restaurants, as most do not even allow only part of the party to be seated for fear of losing a bigger table if the others do not show. If your friends are able to get hold of a table, why not let them? If it helps, you may consider that the host in this case is the restaurant itself. And securing a table is infinitely preferable to being jostled in a crowded hallway.

(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: What is the proper etiquette to join a conversation already in progress?

For example, at a social gathering, a couple of people are already having a conversation. Is it OK to approach the group and say “hello,” or do I approach the group and wait for them to acknowledge me?

When someone approaches my group conversation, I always acknowledge the person right away and share the topic we are discussing. Most of the time, I approach a group and say “hello,” but is this considered interrupting? A few times, I have walked up to a conversation and stood there and was never acknowledged. Very awkward. Help ... I don’t want to be rude, but I love to talk too!

GENTLE READER: Inserting oneself into a conversation in progress, like cutting in for a dance, does have its own etiquette. The newcomer must wait for a lull in the conversation, acting in the interim as if what is being said is both interesting and, even without the preamble, intelligible.

The established group is required to assume the opposite, namely that the newcomer does not know what is being said, and is therefore entitled to a brief, explanatory aside. At the next natural break, introductions can be made all around. While a group holding a conversation in a social gathering should welcome newcomers, Miss Manners warns that such will not always be the case. It is therefore best to actually listen to what is being said, in case it is time to beat a hasty retreat.

DEAR MISS MANNERS: Is dancing to or parodying the national anthem disrespectful?

GENTLE READER: Yes. But isn’t that why you thought of it?

Miss Manners cannot often count on the public to enforce proper behavior, except when it concerns slights to themselves. And perhaps that is just as well. But this would certainly bring it on, and it is not likely to be gentle.

She would advise you to go no further with this idea, which is as unwise as it is unfunny.

DEAR MISS MANNERS: My mother invited her family on a cruise, where we dined nightly in the main cabin. My 54-year-old sister’s manners were a nightmare. My mother was visibly embarrassed in front of her new husband.

I suggested to my sister to follow the level of formality and cues from our mother. She said I was being judgmental. How do you help someone understand that manners matter?

GENTLE READER: Without justifying your sister’s behavior, Miss Manners notes that 54 years is a long time to wait before attempting to correct a problem. At least your sister cannot accuse you of rushing to judgment.

Your mother will need to talk to her, admitting that she bears some responsibility for not speaking sooner. She must resist the temptation to justify her tardiness by blaming it on the newcomer (“your new stepfather was appalled”), as he was minding his own business.

(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 one writes to close friends/family, what are the possible letter endings? And in the case of teachers, which is a suitable letter ending?

Where would it be apt to use “Yours sincerely,” “Yours faithfully” and “Yours truly”? And to which kinds of recipients?

GENTLE READER: You and Miss Manners must be the only people left who use the conventional forms in letters. Others apparently suffer from the current Fear of Formality, believing that anything short of chumminess is snooty -- even in obviously formal situations. Or they may analyze the words and decide that they are not “yours” at all to the recipient, let alone sincerely, faithfully or truthfully.

Thus many letters now open with “Hi” instead of “Dear,” and end with “Best wishes,” “Best regards” or just “Best.” They could do better.

Miss Manners realizes that forms change over the years. She admits that “I remain, sir, your most humble, obedient servant” would not now pass either the truth test or the literal meaning test.

Still, she would like to retain some difference between addressing lovers, strangers and those in between. In formal correspondence, “Yours truly” is the closing for business letters. “Sincerely yours” is for social correspondence short of the love-and-kisses stage, or the more restrained “Fondly yours” or “Affectionately yours” for close friends and relatives.

Which would be suitable for a teacher depends on the content of the letter.

If you are writing to demand a change in your grade, it should be businesslike; if you are expressing gratitude for intellectual enlightenment, the more personal declaration of sincerity would be warranted.

But Miss Manners is not quite so rigid as to exclude a burst of enthusiasm, such as “Gratefully yours,” in the latter case. And those for whom “sincerely” and “truly” are not chummy enough should feel free to toss in a “very” with either one.

DEAR MISS MANNERS: When we were invited to a wedding reception for a co-worker and friend, the invitation made it clear that the event was a dinner reception at a local restaurant. In small print at the bottom, we were told we were expected to pay for our meal due to lack of finances.

We were a bit taken back by this, as the bride and groom had just recently returned from Disney World, but we attended and paid for our meals. A few months later, they had a baby shower, for which we provided food and a gift.

To my surprise, in the mail today we received a save the date for the couple’s wedding -- over a year after the first wedding reception.

How do we respond? I feel we already attended a wedding celebration, and have no reason to attend another. Other friends who’ve been invited are also confused as to how to respond, and feel like this couple is just seeking attention, money and gifts.

GENTLE READER: You think?

Miss Manners advises you to stop participating. She promises you that these people are not planning to stop asking.

(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.)