Comparative law notes
Prior use (defense) in patent disputes Be careful since "prior use" has another meaning under US public law: Prior use (doctrine) refers to a principle that a government agency may not appropriate property already devoted to a public use without legislative authorization. Property devoted to a public use cannot be taken and appropriated to another or different public use, unless the authority to do so has been expressly given by the legislature or may be necessarily implied. In short, the power of condemnation may not be exercised where the proposed use will destroy an existing public use in the absence of specific legislative authority.