DEAR PROFESSOR: Greetings from near Chicago - suburban, semi-rural boredom hell. I really enjoy your books, and I have learned a lot from applying them to real life.

For example, I have learned that most people get quite vicious, or at least upset, if you attempt to explain to them that a story like "The Hook" is an urban legend. So it's best to keep your mouth shut.Thanks for the enlightenment. Peace & Love. - S.S, NEW LENOX, ILL.

DEAR PROFESSOR: If you have any advice on how to gently bring back to earth someone who is telling a story that you know to be an urban legend, I would appreciate it. I am thinking of writing to Miss Manners. - V.A., CASTRO VALLEY, CALIF.

GENTLE READERS: How to respond to someone telling an urban legend as the truth is a serious etiquette dilemma worthy of Miss Manners' attention. But you need not write to America's premiere authority on correct social behavior, since I myself have researched the proper course of action - one that's accepted in all the best spas, country clubs and hair styling salons.

The mannerly method of dealing with someone who is convinced that an urban legend is fact is called the "Polite Persistent Questioning" technique, or PPQ.

Let's take a typical situation requiring the PPQ approach. Say you are gathered with friends on the patio of a fashionable home one moonless evening, sipping expensive Scotch whisky and daintily nibbling an occasional hors d'oeuvre selected from a tray proffered by an attentive servant.

(Actually, the same advice applies if you're on a camping trip toasting marshmallows by the fire, but this example sounds more like a Miss Manners reply.)

Inspired by the atmosphere, someone begins to tell "The Hook," and you, as an urban legend aficionado, recognize immediately that this story is as old as the scotch you're drinking and as phony as the hostess's cosmetic surgery.

Are you expected by the rules of etiquette to "keep your mouth shut" and to endure this recital of falsehoods?

Must you let it stand as the truth that a couple parking on lovers' lane heard a radio warning of an escaped maniac with a hook replacing his lost hand? Or that they sped off at the young woman's insistence and later found a bloody hook dangling from the door handle?

No, indeed. But neither can you simply state outright, "Baloney! That's merely an urban legend that everyone heard at Scout camp years ago."

The socially proper reaction to this situation is Polite Persistent Questioning.

At intervals during the recital of such a legend, you may ask some sweetly phrased - but pointed - questions:

- "Goodness! Why would they give a dangerous maniac a hook? Wouldn't that simply provide him with a weapon?"

- "You mean he reached for the door handle with his HOOK hand? I would think he'd use his other hand for that."

- "Isn't that a remarkable coincidence that the hookman was lurking outside the car just at the moment when the announcement came on the radio?"

- And the best question of all, "But did the young man really walk politely around the car to open the door for his date, after being angry enough to spin his tires as they left their parking place?"

The idea of PPQ is not to pit yourself personally against the storyteller and imply that he or she is lying; that would be a worse gaffe than spreading a legend in the first place. Instead, you should strive to create the impression that you are innocently querying the story's details. This might encourage other listeners to raise further questions.

At just the moment when the narrator seems about to retract the tale, you should rescue the poor soul by saying - as if you just happened to remember it - "Didn't I read about that in a book by Jan Harold Brunvand called . . . oh dear, what was that title?"

At this point, it is considered socially correct to reach into one's billfold or pocketbook and extract a small card on which is written in black or blue-black ink the full titles and publication dates of Brunvand's books and to mention that you saw them for sale at some fashionable boutique.- "Curses! Broiled Again," Jan Harold Brunvand's fourth collection of urban legends, is now available in paperback from Norton. Send your questions and urban legends to him in care of the Deseret News.