DEAR MISS MANNERS: I enjoy the convenience of being able to access the Internet from my home. Lately, however, it seems that whenever I log on to look up a piece of information or dash off a quick note, friends or relatives who have placed me on their "buddy list" are alerted to my presence online and initiate instant-messaging conversations.

I find this unsettling, much as I would if these same friends or relatives received an alert when I picked up a book, turned on the television or pursued any other activity. If I ignore their instant messages, they will know I am online and choosing not to respond.

Is there any polite way to prevent these interruptions? Otherwise, how quickly may I end these conversations without being rude? These are people I would be happy to hear from by telephone or regular email, so I don't wish to offend them.

GENTLE READER: It took a long time for the computer industry to realize that people who were wonders at inventing new gadgets were not necessarily equally adept at fielding customer calls or writing instruction manuals.

Miss Manners has noticed that the industry has yet to make the same realization with regard to electronic manners.

The "status update" that you refer to is an engineer's solution to a manners problem -- and not a good one. One imagines that homeowners who did not wish to receive callers faced a similar dilemma with the invention of the electric light, since throwing the switch alerted everyone on the block that they were home.

Some online systems now allow you to limit such broadcasting of your activities. But for ones that offer no such privacy, politeness does not require that you answer every call simply because you can.

DEAR MISS MANNERS: What is your opinion of people who answer their cellphones when engaged in a conversation?

I understand there may be exceptions for emergencies, but otherwise it comes across to me as rude and makes me feel like second-best. It also breaks our connection -- especially when they can't remember what we were talking about when they end their cellphone talk.

I find it especially annoying when out on a date. Do you think I'm overreacting? What can I say so the other person might be understanding and cooperative rather than feeling put off?

GENTLE READER: Your goal is not to make your date be understanding, but to make her or him unterstand: Taking non-emergency calls while in company is rude.

Expressing interest in the call only condones the behavior, and even risks a rebuke for eavesdropping. And we know that correcting rudeness in others is itself rude.

Miss Manners instead recommends that you excuse yourself and leave the table, returning only after the call is complete. The timing is important -- and also challenging, as your destination is the bathroom, not the bar. Upon your return, apologize for taking so long, but say that since he or she was on a call, you are sure you will be forgiven.

(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: The parents of a recent college grad mentioned that she needed a car (to drive to a new job, hopefully) and maybe related family members could pull together and find her suitable transportation.

One thing grew into another -- aunts and uncles dropped out of the effort -- and I wound up purchasing her a brand-new car off the dealer lot. I even let her pick the color. Red, of course.

Did I ever get a phone call after she picked up the car? No. Did we create a spoiled brat?

GENTLE READER: Apparently that was already accomplished by parents who taught her that if she wanted something they cannot afford, it would be all right to pressure other people to give it to her.

And amazingly enough, you complied.

But the ingratitude is amazing only because of its dimensions. All presents, big or small, require acknowledgment, despite the claim of the beneficiaries that it is selfish of the giver to expect any such return. And those people must be experts on selfishness.

But Miss Manners notes that your relative, who is old enough to be responsible for her own behavior, is acting not only callously, but also against her own future interests. Whom will she turn to when she wants a yacht?

DEAR MISS MANNERS: I received a phone call from a friend who complimented me on my daughter's wedding invitation. We spoke briefly; then she shared with me that her husband had just lost his job. She then asked me if it would be all right if they postponed their gift until a later date, when they would be in a better position financially.

How or what was the best way to handle this? I was totally thrown off guard and had never heard of anyone doing something like this.

My attitude has always been, "If you can't afford to tip, you shouldn't be going to a restaurant." I would have said we are unable to attend the reception due to finances; however, we will be there to see her get married. Am I wrong or being too sensitive?

GENTLE READER: Wrong and insensitive is more like it.

Miss Manners will begin with your etiquette misdemeanors and build up to your crime against the very foundation of manners:

(1) You are wrong that wedding presents must be given at the time of the wedding. Anything up to a year afterward is acceptable.

(2) You are even more wrong to believe that presents are a condition of admission to a wedding celebration.

(3) Your reaction to the misfortune of someone you call a friend is so wrong it is frightening. The correct response would have been, "Don't even think about that. The important thing is that we want you there."

DEAR MISS MANNERS: What should a woman do after she has been kissed on the hand? I am not sure if there is some gesture or response the woman should offer to "complete" the sense of a greeting/acknowledgment.

GENTLE READER: To respond to this gesture is to allow one's hand to be approached.

(Not actually kissed, because a proper gentleman kisses an inch or two above the hand, and would never attempt to do even that to an unmarried lady.)

Miss Manners warns you that this is not as passive or as easy as it sounds. Probably expecting a handshake, the lady will hold her hand stiffly vertical and so must gently rotate it to a horizontal position, allowing him to hold it from underneath while he kisses the air above the back of her hand.

(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 am a hostess in a family restaurant, and today I had a couple of young parents come in with an infant about 7 months old. I seated them in a lovely booth near the entrance of the restaurant.

To my dismay, they changed their baby's diaper right on their table. Then, they signaled me to come over, and when I arrived at their table, the woman held out the soiled diaper and asked me to dispose of it!

I said simply, "I don't have any place to dispose of your baby's diaper, but there is a ladies' room down the hall." She was obviously annoyed and said, "Oh, come on! Surely you can put it in one of the bus trays for us!"

I couldn't help myself, and so I answered, "We don't want your baby's soiled diaper in our bus trays; we cart dishes in those trays."

She became furious and demanded to speak with my supervisor. When she learned that my supervisor was not present, she demanded the phone number for the corporate entity that owns the restaurant, stating that she would make a complaint about me.

Miss Manners, how would you have handled her?

GENTLE READER: Without making physical contact.

Expressing concern for the health and hygiene of other customers and employees is perfectly reasonable, as long as it is done politely. If necessary, you can blame health department regulations.

Miss Manners would hope that any corporate entity would agree -- and assures you that she will be none too quick to frequent the establishment of one that does not.

DEAR MISS MANNERS: There's an urgent situation here regarding this year's lack of rainfall and water shortages. We're all going to have to cut back and be aware of our consumption, or else it's going to get pretty desperate.

One thing that really bothers me is the habit I see at work where certain people will flush the toilet before using it, thus wasting close to 3 gallons of water with each flush!

How can anyone approach these people in a work situation without it looking like they're being singled out? It's very upsetting to hear that we can't grow food while I watch these people at work waste water with each trip to the loo.

GENTLE READER: Put up a sign in the bathroom that says, "Please be mindful of our water shortage and limit your usage as much as possible." By displaying the sign for all, no individual is singled out.

Miss Manners will politely refrain, however, from inquiring as to how you seem so keenly aware of your co-worker's flushing habits.

DEAR MISS MANNERS: My in-laws have graciously contributed a large amount of money for my husband and me to buy a very nice new car.

(1) How do I respond to people inquiring as to how we are able to afford such a nice car, and (2) How do I thank my in-laws?

GENTLE READER: (1) You don't. The question is rude and requires nothing more than a weak smile or change in subject. (2) Profusely.

(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.)