The core group of integration clauses was conveniently grouped together, by the Treaty of Lisbon, in the Articles 8 to 13 Treaty on the Functioning of the European Union (TFEU): these articles cover the equality of men and women, social protection, non-discrimination, environmental protection, consumer protection and animal welfare. One common characteristic of the integration clauses is that they appear more often in policy documents of the EU institutions than in actual EU legislation. Integration clauses may not frequently appear in EU legislative acts, but they are mentioned more often in the impact assessments that precede the adoption of legislative proposals by the Commission. The integration clauses are laid down in Treaty articles they are legally binding and therefore capable of being used by the Court of Justice as a standard for assessing the validity of EU measures or the compatibility of national implementing measures with the Treaties.