Preamble

The introduction of a treaty describing its purpose and objectives in general terms, and often setting out broad principles, objectives, or values.
Not regarded as legally binding, but in the continental legal tradition (but not the Anglo-Saxon) preambles may be referred to by courts as indicating the meaning and intention of legislators.

The EU Court of Justice has often used treaty preambles in this way to justify judgements that have expanded the scope of EU law and competence beyond the strict literal interpretation of a treaty, which is the focus of Anglo-Saxon jurisprudence.