Article 12 of the Treaty of Amsterdam (effective from 1st May 1999) provided that "The articles, titles and sections of the Treaty on European Union and of the Treaty establishing the European Community, as amended by the provisions of this Treaty, shall be renumbered in accordance with the table of equivalences set out in the Annex to this Treaty, which shall form an integral part thereof".

Following the 1999 renumbering in order "to avoid risk of confusion between the version of an article as it stood prior to 1st May 1999 and the version applying after that date"the ECJ introduced a uniform system of citation of the provisions of the four Treaties (ECSC, Euratom, EC, EU) in judgments and in the opinions of the Advocates General.

Further renumbering was effected from 1st December 2009 by the Treaty of Lisbon.

For main notes see European Law/Treaties