Legal Form of the Commons
From the Commons - Typology of Stefan Meretz :
"The legal form shows the possible juridical codes which a good can be subjected to: private property, collective property, and free good. Legal arrangements are necessary under the conditions of societal mediation of partial interests, they form a regulating framework of social interaction. As soon as general interests are part of the way of (re-)production itself, legal forms can step back in favor of concrete socially agreed rules as it is the case within the commons.
Private property is a legal form, which defines the act of disposal of an owner over a thing with exclusive control over the property. The property abstracts from the constitution of the thing as well as from the concrete possession. Private property can be merchandise, can be sold or commercialized.
Collective property is collectively owned private property or private property for collective purposes. Among them, there are common property and public (state) property. All designations of private property are basically valid here. There are various forms of collective property, for instance stock corporation, house owner community, nationally-owned enterprise.
Free goods (also: Res nullius, Terra nullius or no man’s land) are legally or socially unregulated goods under free access. The often cited „Tragedy of Commons“ is a tragedy of no man’s land, which is overly used or destroyed due to missing rules of usage. Such no man’s lands do exist yet today, e.g. in high-sea or deep-sea.” (http://www.keimform.de/2010/01/11/commons-in-a-taxonomy-of-goods/)