In the state of Missouri, there is no difference in the signs. If you are discovered carrying where someone has posted a sign, (and I don't know how they would find out, concealed being concealed) they may ask you to leave. If you don't comply, L.E. Can be called and you are then trespassing.
You need to check the laws where you live.
Same thing in Colorado...if your caught carrying you just leave. However, if you are carrying concealed properly no one will know. I have a GunVault lock box under me truck seat, chained to the frame...I only use it on very rare occasions when I'm unable to carry (i.e. federal building, school, etc.), otherwise it is on me at all times.