Drawing upon her rich experience of life, Prudence (Prudie to her friends) responds to questions about manners, personal relations, politics, and other subjects. Please send your questions for publication to prudence@slate.com. Queries should not exceed 200 words in length. Please indicate how you wish your letter to be signed, preferably including your location.

Dear Prudence,

Tipping waiters is easy enough--15 percent for adequate service, 20 percent if they give me the post-dinner coffee free. But what of those other services that require tipping?

A day in the life presents this newly minted Manhattanite with any number of palms to grease--hands extending from disparately different uniforms and expecting some coinage commensurate with the services their owners provide. They're cabbies, coffee shop waiters, and even official looking guys in old-timey police hats turning the revolving doors for me.

Recently my girlfriend began forcing me to forego my usual visit to the $12-a-cut barber in favor of her "hair artiste" friend, Raoul, who wants not only the customary $50 for the half inch he shears with such aesthetic sensibility from my scalp but also a tip. And bartenders have their own ideas about what it's worth to me to have them put a lime sliver and a tiny straw in my martini.

The question, Prudie, as you may have guessed, is: How much dough should I be shelling out? If I make the bartender mad, the vodka tonics start tasting less like vodka and more like tonic. And if Raoul doesn't get his just deserts, I'm stuck with a $50 bowl-cut. Lately I've been purposely overtipping, just to be safe. At least, I think I'm overtipping. Is five bucks extra enough for an eight block cab ride? The American economy, we're reminded frequently these days, is becoming increasingly service-oriented. And we know what that means. More tips.

Please help.

--Tip o' the Hat, the sober guy at the bar with the bad hair

Dear Tip,

Your letter was so charming that Prudie almost forgot it was about a problem. It was also a reminder that whereas the Hands Out Brigade used to be an issue mostly when traveling, it is now a fixture of everyday life. Prudie, for starters, thinks a $5 tip too extravagant for an eight block ride--unless, of course, the driver provided wonderful therapeutic advice. Most people Prudie has observed tipping taxi drivers tack on a couple of bucks, no matter what the meter. As for people you deal with regularly (like doormen, since you're a Manhattanite), grease their palms once every several encounters, or else you'll go crazy and broke. With people like the artiste Raoul, remain generous--as with the bartender--because some consequences of withholding tips are more noticeable than others. In other words, pick your spots, while at the same time remembering that many service people rely on tips to get by.

--Prudie, balancingly

Dear Prudence,

In your advice column you recently offered this particular bit of "advice": "Prudie finds the appellation 'Ms.' ridiculous and crosses it out whenever possible, believing that single women are 'Miss' and married ones are 'Mrs.' (The nice thing about divorce is that then you get to choose between the two forms of address.)"

MY GOD! What sort of ancient sexist claptrap is this? I, my mother, my grandmothers, and my great-grandmothers haven't been fighting for equality for the past 150 years just to have this dubious woman sweep our work under the rug. I do support a woman who likes to take her husband's name and who likes hearing a solid "Mrs." in front of her name. But in return I expect her support in keeping the stoic, inscrutable "Ms." in front of mine.

--Aries Keck, charter subscriber

P.S. to the editors: Do yourselves a favor--lose Prudence. She's both insulting and inane.

Dear Ms. Aries Keck, charter subscriber,

Prudie is pained by your opinion, as well as by your wish to have her sacked. As for a "dubious" woman, that may not be the word you intended. Prudie does think, however, that "insulting" and "inane" were what you meant to say. Please know that I meant no assault on you, your mother, your grandmothers, and your great-grandmothers.

--Prudie, pacifically

Dear Prudence,

I am a member of the Knights of the White Kamellia of the Ku Klux Klan. I am planning a wedding for my sister, Laura, in Chicago, and I would like to invite some of my fellow members to the wedding. What should we wear?

--Cynthia Comeau in Toledo

Dear Cyn,

Well, certainly not sheets.

Had your name and entire address not been included, Prudie would certainly have thought your letter a prank. Since no rational person would wish to have her name attached to admitted membership in such a shameful group, however, I will answer the question you pose in the spirit in which it is asked.

People should wear whatever attire is appropriate for the time of the wedding. Whether or not it is black tie is indicated on the invitation.

--Prudie, disapprovingly

Prudie ... well, floundered. Fortunately, her readers leapt in to educate her. The error that elicited more letters than Prudie cares to reveal--though all were polite--had to do with a quotation from Thoreau. Prudie will let "Fussbudget From Parma Heights," a k a Neil Swartz, speak for all who wrote to set Prudie straight.

Dear Prudence,

In Slate's Sept. 11 edition, in your answer to "Hope," you discuss the meaning of the relationship between "trout in the milk" and circumstantial evidence. You explain the relationship by saying that if you find a trout in your milk, it is evidence that it was put there deliberately. Either I am dense and missing some subtlety, or you don't understand the origin of the quip.

Some unscrupulous farmers (or merchants) back then made a practice of diluting the milk they sold with water, thus being able to sell water at the price of milk. "Finding a trout in the milk," thus, refers to the inference that this is good circumstantial evidence that water was added to the milk, since the water presumably came from a stream, not that someone deliberately put a fish in the milk.

--Fussbudget From Parma Heights