I have seen so few signs in the 3.5 years I have been carrying that I pretty much never look for a sign. If a mall is no carry it would usually be posted at the various mall entrances but not any of the mall stores that are part of the mall. I have went to stores that were in a mall I knew to have rules against carry and entered/exited the store open carrying without issue and never went in the mall (Kohls/Macomb).