New York City's case for some of the world's most boorish behavior is made every day in its subways: There's the woman casually clipping her fingernails, the man slurping an especially pungent dish under a fellow passenger's nose, and if nature calls, there are the riders who coat platforms with their urine.

Transportation officials are taking a stand against such rudeness with a series of signs in subway cars that would make Miss Manners proud, reminding riders of the most rudimentary etiquette in a tone that's part shaming, part scolding.

"Clipping? Primping? Everybody wants to look their best, but it's a subway car, not a restroom," says one sign, accompanied by an illustration of a passenger squeezed between a primper and a shrapnel-spraying clipper.

Another sign takes on one of the most common complaints — "manspreading" — the practice of (mostly) men sprawling in their seats with their legs spread wide. "Dude ... Stop the spread, please. It's a space issue," it reads.

Says another: "Offer your seat to an elderly, disabled, or pregnant person. Not only is it the right thing to do, but you'll make your grandmother proud."

In Manhattan's busy West 4th Street station, a lone paper sign (which does not appear to be part of an official city campaign) makes an almost pitiful plea: "Please do not urinate in this area."

The Metropolitan Transportation Authority, which oversees a subway system that transports about 6 million riders every weekday, began putting its signs in the subways late last year after it received numerous complaints from riders. The campaign was expanded to buses this week.

It was not clear if the campaign would be expanded further to include other common complaints, including loud music playing, gum-popping or personal hygiene-related odors.

Some riders interviewed this week say the signs are long overdue, even if they don't agree with all of them.

Ericka Phillips, a fundraiser from East Harlem, says she's happy with some of the commands, "like no clipping nails. It's gross! And I've always wanted to do something about the spreading."

"But no primping?" she says with a laugh. "This is New York City, we're all extremely busy and women are judged by looks, so they might want to put on some makeup."

Andrea Dini, a college professor of Italian, says she appreciated the signs but had mixed feelings about the "manspreading" edict.

"If a car is half empty and a man sits like that, why not?"