Post it then!
Show me a law in any state that says you must, or even
may, use the actual word, "posted" on any signage.
What you'll find is that the law says your property must be posted, NOT that you must use the actual word, "posted". To post your property means to
take the action of putting up signs which notify the public of the fact that your property is private. Some states spell out the required wording, or suggest acceptable wording.
By the way, just for your viewing pleasure, here's the Texas penal code on trespassing. Nothing there about putting the word, "posted" on a sign. I've looked at a few states over the years when people have argued this point, and have not seen that requirement yet. Maybe there's a state where the legislators are that ignorant, but I haven't seen it yet.