... That's nice, but I'm trying to come up with a stand alone sticker/decal about the size of the old credit card logos, maybe the size of a business card. Subdued colors so as not to attract much attention. Something we could give out free to places we support so they wouldn't have to do anything but agree to put them on their doors.
I think the notice should be small and as unobtrusive as possible.
"Lawful Concealed Carry Permitted" Something like that.
Many business owners will be reluctant to scare off or frighten 97% of their customers for the sake of 3%.
On the other hand most are entirely unaware of the issue or the law, and it may be best to leave it at that. Suppose you ask a store owner to post a sign saying "Lawful Concealed Carry by License Holders Permitted" and they freak out, start hyperventilating, and post a big "NO GUNZ ALOUD" sign instead?