This sign from Glasgow makes my head hurt

OK. So . . .

1. I have to get permission to trespass.
2. But in order to get permission, I have to trespass on the property to ask if I can have permission to tresspass.
3. Which is trespassing.
4. But once I have permission, I can trespass.
5. But if I have permission, I'm not trespassing.

I figure this person makes his or her living writing federal rules.