CHICAGO (CBS) — As the Centers for Disease Control and Prevention eased mask measures for vaccinated Americans, several private businesses in Chicago aren’t willing to do the same just yet.

As CBS 2’s Marissa Parra reported Saturday, the new CDC guidance has caused a little confusion – because while it says vaccinated people do not need a mask, it does not mean individual businesses cannot still require people to wear one.

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Several restaurants are trying to get ahead of any potential confrontations by making the rules inside perfectly clear – before you even open the door.

“The first reaction was, ‘Oh s**t,” said Josh Leisner, a server in the Loop.

“All of my employees were like: ‘What do we do? What do we do?’” said Michael Roper, owner of Hopleaf Bar in Andersonville.

Roper and Leisner work at different places, but they share the same skepticism.

“We have no way of distinguishing who is vaccinated and who is not,” Roper said.

“If the answer for the vax pass is to show your card, people will pay money to get a fake card before they get a shot,” Leisner said.

CBS 2 has reported on the difficulties of proving vaccination status as it stands right now. Some corporate chains like Trader Joe’s say they will be using the honor system – trusting unvaccinated shoppers to keep the mask on.

But that is a risk Roper is not willing to take.

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“We had to quickly put new signage up,” he said.

The signage said even vaccinated staff and diners need to keep the masks on while walking around.

“I said, ‘The lettering needs to be really bold,’” Roper said. “Maybe this will filter out some people who say, ‘I’m not wearing a mask ever again in my life,’” he said.

As businesses are given freedom to make their own mask decisions, Roper hopes diners can respect his.

“We don’t want to be a COVID spreading zone among people who aren’t vaccinated – for whatever reason they’re not vaccinated,” he said.

Roper also hopes signs in front of restaurants like his will ease pressure from hosts and greeters who have been on the frontlines of confrontations during the pandemic.

Once the mask mandate went into place, Hopleaf actually moved the host station from the back of the bar to the front so that maskless patrons wouldn’t make it very far.

“Restaurant hosts have duties these days that they never had before, it’s a lot harder job than it was in 2019,” he said. “They’re playing a mix of parents and security guard on some days.”

Gov. JB Pritzker and Mayor Lori Lightfoot have said they will be following the CDC’s lead and revising mask guidelines for fully vaccinated Illinoisans. But they have not said how or when.

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Following guidance means they will likely keep mask requirements in places like public transit.