Minutiae abounds!
Isn't that some kind of Mexican soup?
Minutiae abounds!
If you're comfortable with that interpretation of the law, that's fine. The safer interpretation is: if you see the sign, you're aware of the wishes of the business owner. If you're aware of the wishes of the business owner and blow passed the sign, then you're trespassing. The business owner doesn't need to give you any notice before calling the LEOs. When the LEOs arrive, the fun starts.