1 . MEASURES ADOPTED BY AN INSTITUTION - REGULATION - PUBLICATION - DATE ( EEC TREATY , ART . 191 ) 2 . COMMUNITY LAW - PRINCIPLES - NO RETROACTIVITY OF REGULATIONS - EXCEPTIONS - CONDITIONS 3 . AGRICULTURE - MONETARY COMPENSATORY AMOUNTS - RULES - RETROACTIVITY - LEGALITY ( REGULATIONS NOS 649/73 AND 741/73 OF THE COMMISSION )