Now that the Schengen Agreement is part of the Community acquis, it has lost to the EU Member States the status of a treaty which could only be amended in accordance with its terms. Instead, changes are made in accordance with the EU`s legislative procedure under the EU treaties.  Ratification by the former signatory states is not necessary to amend or repeal all or part of the previous Schengen acquis.  Acts setting out the conditions for accession to the Schengen area are now adopted by a majority of the EU`s legislative bodies. The new EU Member States do not sign the Schengen Agreement as such, but are required to implement the Schengen rules within the framework of existing EU legislation, which any new entrant must accept. [Citation required] The agreement would establish Immigration Liaison Officers to advise countries on all new information on illegal immigration and provide advice on the recognition of fraudulent documents. It would also require joint measures for the return of illegal migrants, including joint deportation flights. The Schengen Agreement was the first agreement to permanently remove internal border controls for people at the internal borders of the signatory states, to harmonize the process of controlling the external borders of the Schengen area and to establish a common policy for issuing visas and related measures, such as cross-border police and judicial cooperation of their Member States. The signatories to the Schengen Convention agreed that each Member State can only reintroduce common border controls in certain circumstances.
Denmark also has a unique position with regard to Schengen, because, unlike other Schengen countries, it can decide whether or not to take new decisions under the Schengen agreements. The Benelux countries (Belgium, Luxembourg and the Netherlands) had already set up a common passport area in 1970. In 1984, following protests by truck drivers over delays at border crossings between France and Germany, the two countries signed a bilateral agreement to remove controls along their shared border. In December 1996, two non-EU states, Norway and Iceland, signed an association agreement with the countries that signed the Schengen accession agreement.