The 'JHA acquis' is the body of Justice and Home Affairs texts adopted by the European Union. It is comprised of the TREVI acquis, the Maastricht acquis, the Schengen acquis, the Amsterdam acquis, and the ongoing Lisbon acquis. This combined acquis comprises formal legal measures (EU conventions, EC directives and regulations etc.), cooperation mechanisms (EU framework decisions and joint actions etc.), so-called 'soft-law' measures (decisions, recommendations, resolutions and conclusions), strategy papers (action plans and communications etc.) and reports (implementation, evaluation etc.).
See also the Statewatch Observatory: Council of the European Union: Policymaking through Council "conclusions" (covers policymaking by the Council of Justice and Home Affairs Ministers through the adoption of conclusions, a form of 'soft law' - currently from December 2007 onwards).