Changes made by 1999/435/EC: Council Decision of 20 May 1999 concerning the definition of the Schengen acquis for the purpose of determining, in conformity with the relevant provisions of the Treaty establishing the European Community and the Treaty on European Union, the legal basis for each of the provisions or decisions which constitute the acquis
EU Decision 1999/435
No changes made by 1999/435/EC: Council Decision of 20 May 1999 concerning the definition of the Schengen acquis for the purpose of determining, in conformity with the relevant provisions of the Treaty establishing the European Community and the Treaty on European Union, the legal basis for each of the provisions or decisions which constitute the acquis are recorded.
From legislation.gov.uk's record of changes, the official one: see it there.