[1] Under some systems using this method of acquiring ownership of land, it is permitted to employ violence in defending the duly appropriated holding against encroachment against the ownership or usage claims, again usually according to specifically defined forms including warnings to the encroaching party, exhaustion or unavailability of duly constituted law-enforcement resources, etc.. Libertarian and other property-rights-oriented ideologies define appropriation as requiring the “mixing” of the would-be owner's labor with the land claimed.
[2] A prime example of such mixing is farming, although various extractive activities such as mining, and the grazing of herds are often recognized.
Personal, physical residence is often recognized after some minimum documented continuous period of time, as is built structures on the land whose ownership has not previously been recognized by the authority whose recognition is sought.
Appropriation has been applied under common law to resources as disparate as radio broadcast frequencies and Internet Web site names[citation needed], but many such claims have been overturned through legislated arrangements mandating other standards for the assignment of ownership rights in such things.
Appropriation as a means of acquiring property is related to the schools of thought that call for ongoing use as a condition of continued ownership, as is the case in some regimes with trademarks, but it applies to initial ownership.