I ignore all signs that do not meet the state requirements only if I have a need to go there. As a rule I try to avoid all places that have any sign. One example is my bank. They have a small sign in the door that states; NO FIREARMS ALLOWED. I ignore it every time I go in. The law is clear just any sign will not suffice. The law states that signs MUST be a certain size, color, letters and position. Any other sign will not meet the requirements. This is about as clear a law can be. Must means Must.
SECTION 23-31-235. Sign requirements.
(A) Notwithstanding any other provision of this article, any requirement of or allowance for the posting of signs prohibiting the carrying of a concealable weapon upon any premises shall only be satisfied by a sign expressing the prohibition in both written language interdict and universal sign language.
(B) All signs must be posted at each entrance into a building where a concealable weapon permit holder is prohibited from carrying a concealable weapon and must be:
Do a Google search and you'll find all kinds of discussions on this subject. If you get caught carrying in a place that has a sign that meets the requirements the you can be arrested and pay the consequences. If you get caught carrying in a place that has a sign that does not meet the requirements then all that can be done is to ask you to leave. If you fail to leave then you can be arrested for trespassing.
I just called SLED and talked to the regulatory department and she stated that Signs must meet the requirements as prescribed by law. She stated that if they don't meet the requirements then all they can do is ask you to leave. If you fail to leave then they can call LE and you could be arrested for trespassing. You can call Concealed Weapons Permits, Security Guard, and Private Investigator Questions at 803.896.7099 and verify if you like.
I've never been noticed nor have I known anyone that has. If you CC correctly you'll never be noticed.