Conspicuous signage needed on the entrance? I've carried into Costco as a guest not knowing they didn't allow carry, not for sure if I would do it again , last time I was at Costco I locked up my firearm, I think it's just easier to go to Sam'a Club where my firearms are welcome.
I've carried several times in Westroads mall in Omaha and later found out they have rules posted somewhere that says no weapons ?
After doing some research I found that the State Fair does not allow guns which I locked up my firearm before entering only to find it is NOT posted, I had to go through the State Fair program to find weapons are not allowed , not for sure if I want to get caught carrying there , after locking up firearm I found out the next day many vehicles had been broken into.
The list is much longer than the one posted of anti-gun businesses that don't advertise it.
Hallmark
Sonic
Target
Starbucks
Levi Strauss
Time Warner.............just to name a few.
For example if I'm buying clothing I steer clear of Levis or if I'm purchasin a card I will not buy from Hallmark, if I get a cup of coffee I go to Dunkin Donuts, the coffees much better . If there's an alternative that's where I spend my money.
Google is a hard one to get around but when using a search engine I use Duckduckgo, they are gun friendly and don't track your searches.👍