Art 189 (renumbered 249) of the Treaty of Rome provides for the EC Council and Commission to "make regulations, issue Directives, take decisions, make recommendations or deliver opinions".

Together these constitute "secondary legislation" (in contrast to the various treaties, including the Treaty of Rome itself, and conventions which are "primary legislation").

The "principle of subsidiarity" was adopted as art 3b of the Maastricht Treaty. This limits direct intervention of EC rules into domestic laws of Member States, save where "the Community has a clearly defined and undeniable obligation to act. However, in areas of shared competence, Community action should not be the rule, but the exception to national action".

Renumbering of Treaty of Rome articles was effected by Article 12 of the Treaty of Amsterdam as from 1st May 1999 (see European Law/Renumbering of Treaty articles ).

In general, the difference between directives on the one hand and regulations on the other is that a directive requires individual Member States to transpose its requirements into national law to implement it whereas a regulation appplies throughout the EU without more.

Two other significant parts of the EU legislative process are EC decisions which bind those to whom they are addressed and EC communications which are preliminary documents, often followed by proposals for legislation.

See also European Law/direct applicability of EC or EU measures .