I’ve often seen signs on private property that say “Posted No Hunting”. Why the “Posted”? Why doesn’t just “No Hunting” suffice?
Just a WAG: Probably the legal requirements to convict someone of criminal trespass in the state require that a notice be given verbally or be “posted.” So the sign is pre-printed with the term “posted” just to reinforce the idea to the would be trespasser that “Yes, this sign is telling you to stay off or else.”
It is a little weird, sort of like having a sign say “this sign says no hunting” instead of just “no hunting”. But I imagine its what jjtgain says, the language is to make clear that the sign is there to meet the legal requirement of “posting” a sign, and make sure someone can’t claim they thought it was hung there by PETA or someone to protest hunting in general.
“Posting” is a very specifically defined-in-law way of warning off trespassers. You need signs of a certain size and description, posted in a certain way in relation to the property line, and with a certain frequency. So yes, the signs you see are asserting not only that the owner doesn’t want hunters, but also that the legal requirements of “posting” have been met.
I once posted some family property, then made a second circuit around the perimeter to confirm that my signs were properly visible in accord with the rules. And damned if there wasn’t a guy perched in a portable tree stand right there! He was overlooking a field, hoping for deer to emerge from the opposite tree line. I was astonished, but had the presence of mind to order him down and march him back to the house, where I called the game warden. When he arrived, I showed the warden the exact tree where I’d found the guy, and he readily agreed that my posting had met the legal and practical requirements; there was no way the would-be poacher could have got to that spot without seeing at least one of my signs.
This may help: Posted Definition & Meaning - Merriam-Webster