Possession... that is to imply a system of property that is at odds with capitalism. I mean possession, use and occupancy in the Proudhonian and Tuckerite tradition. We are talking about, on one hand, a system of property based on "use" and on the other, one based on "absentee ownership."
I read some of your link.
I am not an anarchist, but they got one point right in the "What kinds of property does the state protect?" part.
They pointed out that even if libertarian recognizes the power of state of enforcing property, most of them never consider that the listing of what can be private property is a form of statism.
I fully agree, protection of intellectual property, or artificial property like gov issued licences of any kind is a form of statism, that is against free market.
However, most people think capitalism is equal to big business, and think that governement policies that protect big industries are in favor of capitalism.
But this is statism, not capitalism, state backed monopoly is not capitalism.
I am no more in favor of sanction from governement to big business (like anti trust law), than in favor of walls of protection. (licences, as well as intellectual property)
But I am not an anarchist, because without the concept of private property, your only way to defend against looters that claim higher utility of a piece of land than you is violence.
I am against any premise that say landlord exploits workers when both deal with each other without coercion. They chose, with their free will to be exploited if they think they are.
If they are not happy with it, they can fund a cooperative and distribute rent among them, without any landlord. The concept of state enforced private property does not prevent them from doing that.