Hierarchy of acts
Today, there are only two levels of EU legal acts, treaty articles and so-called secondary law - regulations, directives, decisions, recommendations and opinions. Verdicts of the EU Court in Luxembourg could equally be considered on a treaty level.
The European Parliament adopted the Bourlanges-report on the hierarchy of EU acts in December 2002.
The Convention discussed an additional higher level of legal act including "organic laws". This refers to measures between treaty articles, EU law and framework law, but this was not adopted in the EU Constitution nor in the Lisbon Treaty.
See also the Convention working groups, Simplification, Primacy, Regulation and Delegated acts.