From M. Walberg with the Chicago Tribune:

With the application process for concealed weapons beginning this month, business owners who want to keep guns out of their establishments need to follow Illinois State Police guidelines on what signs may be displayed.

A copy of the sign that must be used is posted on the agency's website to be downloaded. It features a red circle and slash over the black silhouette of a handgun with the phrase "Pursuant to 430 ILCS 66/65" in the bottom right corner.

"If the sign does not meet statutory specifications, it would not be valid, and it could potentially be problematic to maintain criminal charges" against violators, State Police spokeswoman Monique Bond said.

Under the law, concealed weapons permit holders can be charged with misdemeanors and have their permits suspended or revoked for carrying a weapon on the property of a business with posted signs banning them.

The statute also bans weapons in a host of public areas, including courthouses, schools and government buildings, and inside public transportation facilities or vehicles. Permit holders who bring a weapon into any of those types of locations can face felony charges.

Bond said the sign must be no smaller than 4 inches tall by 6 inches wide, but said businesses can opt to make the sign larger if they believe it is necessary.

Meanwhile, many of Chicago's major office building owners and managers are still deciding how to handle the issue.

"We're getting a lot of calls about the signage," said Ron Tabaczynsky, director of government affairs for the Building Owners and Managers Association of Chicago.

The approaches are generally falling into two camps, he said. Although some are issuing a blanket prohibition, "others are taking the tack that this is a concealed carry law, there's a licensing procedure and a background check, and they're going to put their faith in that," Tabaczynsky said.

Most building owners and managers, he said, are more concerned about security and liability issues — despite provisions in the law that protect companies from being held responsible for incidents that involve concealed weapons permit holders.

A few may have concerns that customers might object to their position, but businesses in other states found that public reaction to the signs quickly lessened, Tabaczynsky said.

"What we pretty much found was there was an adjustment period, and after that it wasn't a really big deal," he said. "People came to view the posted notices much in the same way they view the no-smoking signs."