Factors in favour of Croatia's preservation of its pre-war borders were the Yugoslav Federal Constitution Amendments of 1971, and the Yugoslav Federal Constitution of 1974. The 1971 amendments introduced a concept that sovereign rights were exercised by the federal units, and that the federation had only the authority specifically transferred to it by the constitution. The 1974 Constitution confirmed and strengthened the principles introduced in 1971. The borders had been defined by demarcation commissions in 1947, pursuant to decisions of AVNOJ in 1943 and 1945 regarding the federal organization of Yugoslavia.