Lame…
“No Weapons Allowed” Signs Enforced? Yes. All signs must be posted at each entrance into a building where a concealable weapon permit holder is prohibited from carrying a concealable weapon, whether openly or concealed and must read, ‘NO CONCEALABLE WEAPONS ALLOWED’.
[S.C. Code Ann. § 23-31-235 and, as of 8/16/2021, § 23-31-220]
However, municipalities may temporarily restrict the otherwise lawful open carry of a firearm on public property when a permit is issued for a public protest, rally, fair, parade, festival, or other organized event by posting signs prohibiting concealable weapons.
[S.C. Code Ann. § 23-31-210(5)]
A public or private employer may post signage prohibiting concealed and/or openly carried firearms on the premises of the business or work place. They may also prohibit firearms while using any machinery, vehicle, or equipment owned or operated by the business.
[S.C. Code Ann. § 23-31-220]
https://www.usconcealedcarry.com/resources/ccw_reciprocity_map/sc-gun-laws/