Garys
NES Member
the place has to earn 51% or more of it's revenue from alcohol to post the 51% sign (prohibiting carry). Most restaurants don't make 51% from alcohol.
The only place I ever saw a red 51% sign was the function hall at Southfork Ranch. The one for the TV show Dallas. It's a tourist attraction now and they do weddings and such at a big hall on the property. Other than that, I've never seen one.
I still don't quite understand the blue signs that seem to say that it's illegal to carry illegally on the premises.