Here's an interesting aside on the subject. While I never see anyone open carrying, not yet, anyway, I do see the 30.07 sign from time to time. However, the aside I am about to note is even more interesting.
First, I am aware of an office of a medical laboratory company that is inside a medical building in Dallas with both a 30.06 and a 30.07 sign. The building itself has no sign. Thus, the two signs apply solely to the laboratory company.
Second, even more interesting, there is a county building here that had a 30.06 sign on its main entrance for years. That sign is now gone. However, in front of one small, upstairs, internal room that is used for hearings, in the nature of a courtroom for want of a better explanation, there now exists a 30.06 and a 30.07 sign. The application thereof is, therefore, limited solely to that one small hearing room.
On the first, main floor, in the lobby, there is an armed police officer. I asked her what she would do if someone entered the building carrying a handgun openly. Her reply? "Nothing."
Someone in the county decided to limit handguns to the hearing room only. Weirdest thing I ever saw in this context.