"The Convention establishing Europol under Article K3 of the Maastricht Treaty was agreed in 1995 and, after ratification by the Member States, came into force on 1 October 1998. The Convention specified what Europol should be, what it should do, and how it should do it. Under the Convention each Member State was required to designate a national unit to liaise between its own competent authorities and Europol. The national units would second at least one liaison officer to Europol headquarters to represent the interests of their national authorities and to facilitate the flow of information in both directions." (Quoted from article)