(b) Notwithstanding the provisions of subsection (a), a person, including a person with a permit issued under Section 13A-11-75(a)(1) or recognized under Section 13A-11-85, may not, without the express permission of a person or entity with authority over the premises, knowingly possess or carry a firearm inside any building or facility to which access of unauthorized persons and prohibited articles is limited during normal hours of operation by the continuous posting of guards and the use of other security features, including, but not limited to, magnetometers, key cards, biometric screening devices, or turnstiles or other physical barriers.
(c) The person or entity with authority over the premises set forth in subsection (a)(1)-(6) and subsection (b) shall place a notice at the public entrances of such premises or buildings alerting those entering that firearms are prohibited.