[4] Schengen Information System (SIS), European Commission, Home Affairs, ec.europa.eu/dgs/home-affairs/what-we-do/policies/borders-and-visas/schengen-information-system/index_en.htm (last updated 31 August 2012). Since 1999, the Schengen acquis (legal body) has been integrated into the legal framework of the European Union. The key provisions of the Schengen Borders Code, created by Regulation No 562/2006, are the abolition of internal borders between the Schengen States and the parallel strengthening of the external borders of the Schengen area. The abolition of internal borders guarantees the free movement of EU citizens and qualified third-country nationals. Third-country nationals are subject to thorough checks on entry into and exit from the Schengen area, while EU citizens and other persons enjoying the right to free movement are subject to minimum identity checks. One of the key features of the Schengen area is the Schengen Information System (SIS), a vast database used by the competent national authorities to ensure public security in the Schengen area and to ensure effective management of the external borders. Participating countries are primarily responsible for the management of their external borders, while being allowed to conclude bilateral agreements with neighbouring countries with a view to implementing a local border regime. In addition, the Schengen countries reserve the right to re-establish internal controls for six months in exceptional cases. In December 1996, two non-EU states, Norway and Iceland, signed an association agreement with the signatories to the agreement to become part of the Schengen area. Although this agreement never entered into force, both countries became part of the Schengen area after similar agreements were concluded with the EU.

[9] The Schengen Convention itself has not been signed by non-EU states. [10] In 2009, Switzerland concluded its official accession to the Schengen area with the adoption of an Association Agreement by referendum in 2005. [11] [30] Anna Sonny, Commentary, Schengen Disputes Continues, Civitas (Institute for the Study of Civil Society) (8 February 2013), civitas.org.uk/newblog/2013/02/schengen-dispute-continues/. In September 2011, the Commission proposed an amendment to the CBS and called for more «EU-based governance» to assess the implementation of the Schengen rules. . . .