Just a couple things to add to the word interpretation... I've read on here, somewhere, that if an improper sign were to be posted, such as a 51% sign at a liquor store (on premise consumption clause), that TABC could be notified and the owner forced to remove the sign. Wouldn't the proper terminology then, be
'illegal' ?
Secondly, I was told at my renewal class something I didn't know or remember from before. Signs such as the one shown in the OP is for unlicensed carry, obviously, so it would not be proper to put a 30.06 sign up at the same location as they would be contradictory. It was instructed to us that the OP's sign example actually
authorizes legal concealed carry and a 30.06 would contradict that so it
can not be posted. So, depending on how you treat my first statement, a properly created 30.06 sign would be invalid/unenforceable or illegal.

I believe there is safety in numbers..
numbers like: 9, .22, .38, .357, .45, .223, 5.56, 7.62, 6.5, .30-06...