You needn't talk quite so loudly. Miss Manners had already noticed that you have a portable telephone.

One of these days, she is told, everyone will have one. There will be cheap, miniature telephones available that can function anywhere. No one need ever again be stuck with having to talk to the person he or she is actually with.

Technology is a wonderful thing. But sometimes it reckons without the even more awe-inspiring force of etiquette. Just because something can be done, that doesn't mean it may politely be done.

Miss Manners understands that for the owners of portable telephones, the No. 1 etiquette hazard is embarrassment. There is hardly any more public wallflower than the person who is obviously lugging around telephone equipment in a bag that never seems to ring.

And it is, of course, Miss Manners's duty to sympathize with all etiquette problems. But she allows herself some discretion about which ones to suffer over first. In the matter of peripatetic telephones, she worries first about the non-users present who are being annoyed.

There are other victims -- those who are being telephoned relentlessly, just when they thought they had a few minutes' respite from their bosses or talkative acquaintances who had gone out. There is a lot to be said for not being able to be in touch with everyone all the time.

But etiquette favors people who are actually there in the flesh over disembodied voices -- a principle that most telephone devotees have failed to master. Not even greed seems to be strong enough to allow business people to ignore the unknown and tentative propositions represented by a ringing telephone in order to accept real money from actual customers on the scene.

In protecting the rights of those who are either disturbed or ignored by wandering telephoners, Miss Manners does not intend to validate the complaints of people who are offended merely by the existence of the equipment, whether or not its use affects them. People who want to tattle on those they have observed telephoning from cars ought to be keeping their eyes on the road ahead of them. Anyone who wants to do his or her work in an airplane or hairdressing establishment, or while standing in line at the bank, has Miss Manners's blessing.

The offense is not in talking on the telephone, much less in owning the equipment with which to do this. It consists of intruding on others, or neglecting others, to do this.

You wouldn't think Miss Manners would have to tell people not to take telephones to concerts and parties. But that's only because you have not received the reports she has and still have faith in the ability of your fellow citizens to exhibit a modicum of taste.

It is not only the noise, as in the case of a concert, that violates propriety. Many gatherings, including all social events, are spoiled by being turned into obvious places of business. Unobvious business isn't supposed to be conducted there either, but one would have to commit the error of eavesdropping to make sure conversations were not taking a commercial tone. But any equipment -- not only fancy stuff, but papers as well -- is out of place.

A person dining in a restaurant alone would technically be allowed polite usage of the telephone, which would be a grave offense if there were another person at the table. But then it might be considered rude of such a person to take up a table at all while others want to dine -- because that pesky old rule about not talking with one's mouth full still applies.

I met a fellow from out of town without a proper introduction, and after three months of living with me, he adamantly refused to tell me what he did (or had done) for a living, attributing to Miss Manners that my asking was rude.

Two months later I asked him to leave, because he wasn't significantly contributing to the well-being of the household. When I moved to his state (I sent out moving announcements) half a year later, his concerned mother tracked me down, looking for him. Among other things, she informed me that this well-educated, upper-middle-class fellow had been living in his car for five years.

Was it incorrect of me to ask what he did?

Now have you learned the value of proper introductions?

Good. The next lesson is not to take etiquette advice, even if it spuriously carries an impeccable name, from those to whom you have not been properly introduced.

Intimate questions may be asked by those on intimate terms. But in this case, even Miss Manners could have figured out the answer without asking.