I don't think there is a "legal" or stipulations on signs. If I remember correctly the law says the sign has to be within ten feet from the property entrance.
No wording on what it has to say other than the "No guns allowed" thing. So basically whatever pictures they show there should be understood they mean ANY firearm.
I've heard if you have the enhanced CCW permit you can CC even with a sign. But haven't had the chance to verify that.
Wrong, wrong, and wrong on the sign!
MS Code 45-9-101(13) is what contains the sign definitions you refer to. You're a bit off on the requirements - there is a
specific phrase quoted in the statute for the sign to be compliant, and it must be
visible within 10 feet of every entrance. However, 45-9-101 defines the "license to carry stun gun, concealed pistol or revolver", and has nothing to do with weapons outside of the types named in the title. The pictures on the sign mean
nothing when it comes to the legality of the sign.
45-9-101(13) said:
<snip>
the carrying of a stun gun, concealed pistol or revolver may be disallowed in any place in the discretion of the person or entity exercising control over the physical location of such place by the placing of a written notice clearly readable at a distance of not less than ten (10) feet that the "carrying of a pistol or revolver is prohibited."
<snip>
Now whether the sign itself (regardless of compliance with 45-9-101(13)) would count towards a notice of trespass, would be defined in Mississippi's trespass statutes. I'm not at all familiar with the statutes on trespass, so I can't comment at all.
Regarding the "enhanced" permit and compliant signs... A strict reading of the new language in 45-9-101(13) leads me to believe that the enhancement does nullify even the compliant signs. I seem to recall hearing that the AG(?) had made some kind of statement as such, also, but I wouldn't swear to it. As I said before though, this ONLY applies if you are carrying a "stun gun, concealed pistol or revolver" according to the permit's definition.
http://www.lexisnexis.com/hottopics/mscode/ is my source. The site's structure doesn't allow for direct links to the statutes, so you'll have to drill down to the relevant sections yourself.