++++ Social security for migrant workers ° Family allowances ° Regulation No 3427/89 establishing with effect from 15 January 1986 a uniform arrangement eliminating any difference depending on the Member States of employment and residence of the members of the family ° Whether national legislation limiting to six months the retroactive effect of applications for family allowances may be applied as against a Spanish worker claiming backdated benefits (Council Regulation No 1408/71, Art. 73, as amended by Regulation No 3427/89)