The person being trespassed against would ideally gain that type of information before acting.
Technically you can be a slave and sovereign at the same time, like how a cop can be off-duty. They can't really tell what property belongs to what version unless you register it. So everything beyond car and land would be ambiguous.
Indeed, it would applied only to registered belongings.
As for the unnoticeable trespasser, I agree with you, on a practical view.
But do you get the dilemma on a more theoretical view.
To solve this you can only :
And both are imperfect cause,
He initiate no harm to anyone, an if he get noticed with something he can't understand, you can't say he willingly trespassed.