Just when you think there couldn't possibly be another battle over the behavior of homeless people in San Francisco, along comes a new brouhaha among the stacks at the city's Main Library.

The Civic Center building has long been a bastion for transients, some of whom have forgone good old-fashioned reading for bathing in the bathroom sinks, dealing drugs and exposing themselves. Recent notable incidents include a man urinating on books and another breaking a computer with a hammer.

In January, Mayor Ed Lee told the Library Commission that the facility needed to be less "Lord of the Flies" and more "Sense and Sensibility." (Those are our words, not his, you'll be stunned to learn.)

The mayor's letter to the commissioners proposed creating a Family and Education Fun Zone around the library and suggested that the first step should be instituting actual penalties for breaking the library's long-standing code of conduct. Previously, most bad behavior was met simply with a warning to stop.

In response, library staff beefed up the Patron Code of Conduct with much harsher penalties than the admonishment, "Uh, that's a sink - not a bathtub." Under the proposals, which will likely be tweaked after community input and voted on by the commissioners this spring, repeat offenses could result in being banned from all the city's public libraries for up to a year.

Library administration would circulate a description of the suspended person to managers at its branch libraries, though it's hard to imagine how the ban would work since there aren't ID checks to enter a library. Suspended persons would get a letter notifying them of the ban and telling them they could request a hearing to try to get it overturned.

"The mayor definitely thinks it's a step in the right direction," said Christine Falvey, spokeswoman for Lee. "He is happy that they've really responded with some very substantive changes that have stricter penalties associated with bad behavior at the library."

Falvey added that the mayor wants everybody to behave well at the library and does not want "to single out any population."

City Librarian Luis Herrera agreed, saying, "It's not targeted at any one group - this is a very welcoming environment. It's about making sure people use the library for its intended purpose."

But homeless advocates aren't buying it. After all, who else is likely to bring carts into the building, sleep on the furniture or emit a "strong, pervasive odor" - all of which would be grounds for suspension?

Jennifer Friedenbach, director of the Coalition on Homelessness, said the odor rule is just plain mean.

"You'd have to ask the library how that would work," she said. "Is there a senior sniffer, a supervisory sniffer, and are they the ultimate judge of what is a bad body odor? I know what I smell like when I don't put deodorant on, and it's not pretty."

Herrera said staff, including an in-house social worker, would be discreet in such instances, asking the person to speak in private and sharing information about social services, including places where homeless people can shower and do their laundry.

"We don't want to call anybody out," he said.

Behavior at the Main Library is getting better overall, library staff points out. Since late last year, the library has hired seven extra security staff members, and more police officers are patrolling the building as well. There were 238 incidents of problematic behavior at the library in December, 183 in January and 148 in February. Considering that 5,000 people use the Main Library every day, that's not too bad.

Across all public libraries in the city, instances of bad behavior are down 32 percent in the past two years.

"The odds of you actually being around an incident are very low, lower than if you're in other parts of the city," said Roberto Lombardi, facilities director for the library.

The library is using new incident tracking software so staff can easily see when and where particular behavior is spiking and respond by sending extra security. In addition to the Main Library, libraries that have seen their share of trouble include the Mission Bay, Chinatown, Mission and Excelsior branches, library staff said.

The most common broken rule is sleeping in the library, followed by the generic "creating a disturbance."

"That might just be somebody who's mad that their book isn't there," Lombardi said.

Hey, when you want that hot new best-seller, you want it now.

In any case, in reading through the proposed code of conduct, some observations come to mind. Like that it's sad that it actually needs to be written down that people are not allowed to deposit bodily fluids on books, physically abuse staff or have sex in the library. And that the guidelines may occasionally go over the top.

Like the no-staring rule. Really?

Herrera laughed and explained that some staff members have reported being stared at in a threatening way.

"It is subject to interpretation," he acknowledged. "We understand there's room for improvement."

Quote of the week

"I just want people to leave me alone. I just want to do my Elmo stuff."

Dan Sandler, a.k.a. "Evil Elmo," who has irked Fisherman's Wharf merchants and street kids with his creepy shtick