In my state our CCW advocacy/lobbying group has done a lot of good work. One such victory is that we got the legislature to spell out very specifically what constitutes a valid "no CCW" sign. The sign's size, color, language, placement and symbology are all spelled out in great detail. For premises that have multiple entrances, every publicly accessible entrance must have such a sign. In "open air" venues the signs must be huge (3 feet by 4 feet, mounted at a certain height like 5 feet off the ground). Any business/entity that posts against CCW and does not make their signs like this has no legal standing for their anti-CCW action.

Do we go out of our way to notify businesses whose signs don't meet the code? No, we do not.