Hold on a minute -- it's the Call Waiting people ringing in. They're an impatient lot, perpetually living in a state of potential emergency, and cannot stand to be kept waiting.

Some weeks ago, you may recall, Miss Manners delivered herself of the opinion that as the human being is capable of taking only one telephone call at a time, politeness demands that one take calls in the order in which they were made.

She noted that the busy signal was invented precisely to inform successive callers that the person they were attempting to reach was busy. To widespread declarations that encountering such signals are maddening, she responded that it was not the signal itself, but the absence of instant availability to one's summons that was unreasonably considered intolerable.

She also ventured timidly to say that there must be other people who, like her, would find that life would go on just as well if they were not always dropping what they were doing in the expectation that something better was coming along -- at such a clip as to disappear if it were not immediately grabbed.

You will never see Miss Manners breaking into a line, exclaiming, "I'm in a hurry," as if she imagined the others in line to be there merely to pass the time of day. It is her belief that a little humility and patience, along with the practice of always having a good book within reach, would enable each of us to endure whatever waits life bestows upon us.

She therefore concluded that a device designed to allow one to interrupt a conversation for the express purpose of informing someone else that one was already having a conversation was unnecessary at best, and rude at worst.

Well, my goodness. In came the mail. By Miss Manners' modest standards -- she is not the columnist to ask people to confess their romantic proclivities; on the contrary, the burden on modern etiquette is to stop people from constantly volunteering these -- there was a lot of it.

Nearly all of the proponents of Call Waiting cited family reasons for employing it, and had the ill grace to suggest that Miss Manners either probably didn't have any family or never cared to hear from them.

The argument was that Call Waiters wished to give family business priority over telephone visiting:

"Perhaps a phone call from a son or daughter saying they'll be home later than expected is not important to you. But in these days of missing children, I consider even five minutes of worrying about why they aren't home at the regular time a most upsetting occurrence . . . I have three children in school, a husband who works with dangerous machinery 10 hours a day, a widowed mother who lives alone and my only sibling (since the death of a sister) is a brother in Texas."

"We have three children in three separate corners of the United States attending college. For their peace of mind, as well as ours, Call Waiting has been a godsend . . . Parents have enough guilt feelings about their availability when it comes to children."

"Before we had Call Waiting, I was constantly getting complaints from my husband about trying and trying to reach me and just getting a busy signal, and all he wanted was some crucial quick answer I could have given him in 30 seconds."

And so on. Each of these people swore up, down and sideways that the interruptions were made only for pressing family business. Miss Manners does not quarrel with the laudable desire to keep oneself free for one's family, but suggests that doing so precludes simultaneous entertaining of guests. One visits with people when one has leisure to pay attention to them, not when spouses and children need one's attention.

The Call Waiters also promised that they always treated their original callers with high consideration, and never, ever asked them to hold on for more than a second needed to attend to emergencies.

Perhaps not. But, then, why are there so many other letters with similar stories of being put on hold, only to be blithely informed, when remembered, of a subsequent telephone visit?

None of these reports described to Miss Manners turned out to be children calling in with broken necks.