SAN FRANCISCO -- There is a line between being tolerant and having no standards whatsoever, and that's a line that San Francisco passed a long time ago. Public nudity has become the costume de rigueur in certain corners of the Special City. Twice in the last year, I've see groups of nude adults walking or biking around the Embarcadero - to the delight of some tourists and the disgust of others.

"Clothing-optional" could be the city's new motto, along with "age-inappropriate."

In a well-meaning - dare I say, modest? - attempt to address the Special City's new normal, Supervisor Scott Wiener has proposed a measure to require that nudists not sit or eat in public without "clothing or other separate material as a barrier between his or her genitals, buttocks, or anal region and the public seating." The ordinance language - like its targets - commits the offense of exposing too much information.

"San Francisco is a liberal and tolerant city, and we pride ourselves on that fact," Wiener said in a statement. "Yet, while we have a variety of views about public nudity, we can all agree that when you sit down naked, you should cover the seat, and that you should cover up when you go into a food establishment."

In other words, people who walk around naked somehow are supposed to exhibit taste and consideration.

Wiener represents the Castro, where a number of nudists like to congregate and digest. And a number of constituents don't like it one bit. "Let me tell you, this is an issue," Wiener told me.

Wiener is especially unhappy that he is "the first politician who has touched this issue in any respect" - and yet, he believes, the media have slammed him for not going far enough in not pushing for an all-out ban on public nudity itself.

Why not an all-out ban? The state penal code prohibits a person exposing private parts publicly "where there are present other persons to be offended or annoyed," but some judge decided that police can't decide what's offensive except for outright lewd acts.

City Hall follows a strict interpretation of state law, so the city prohibits police arrests for public nudity absent a citizen's arrest.

Other cities have ordinances that explicitly ban nudity in public, but SFPD public information officer Albie Esparza explained, "We don't have that in San Francisco."

Or as former district attorney spokeswoman Debbie Mesloh told the Chronicle in 2004, "Being naked in San Francisco is not a crime unless the gentleman had lewd conduct or was obstructing traffic."

Now, I've seen worse things in this town than a gaggle of sagging nudists. To wit: public defecation, panhandlers yelling at passers-by and substance abusers who hate themselves so much that they want to foul up the whole neighborhood.

And I think the human body is a beautiful thing - but not for everybody, not always and not everywhere.

Public nudity involves a lack of privacy so blatant that it invades the privacy of others. It is inappropriate in front of children. It has become a quality-of-life issue - another in-your-face assault on the city's (there's a reason for this language) social fabric.

Sadly, the city is so paralyzed with political correctness that solons can only go after public nudity when it's unhygienic.