The business owners right's law came to be when a company searched their employees cars in the parking lot and everyone who had a firearm in their car was fired. Those that wouldn't allow them to search their cars were fired.
Now if you reread the law with that in mind you will see that the law says:
TITLE 21 § 1290.22. Business owner’s rights
BUSINESS OWNER’S RIGHTS
A. Except as provided in subsection B of this section, nothing contained in any provision of the Oklahoma Self-Defense Act, Section 1290.1 et seq. of this title, shall be construed to limit, restrict or prohibit in any manner the existing rights of any person, property owner, tenant, employer, or business entity to control the possession of weapons on any property owned or controlled by the person or business entity.
B. No person, property owner, tenant, employer, or business entity shall be permitted to establish any policy or rule that has the effect of prohibiting any person, except a convicted felon, from transporting and storing firearms in a locked vehicle on any property set aside for any vehicle.
As you can see it doesn't allow a company to make a policy that would prevent a person from locking their gun up in their car.
If you still think you can't carry in a posted business that isn't a government building or school, then good luck to you. I'll be the one defending my loved one while yours is hiding in the corner hoping I stop the BG before they get to you.
Concealed means concealed. I am a law abiding person if I conceal carry anywhere except government building and schools.
The only way a jury will know I had a gun in a posted business is if I had to use it. Since there is no clear law on signs, I'll take my chances.
Better to be tried by 12 then carried by 6.