1 . FREE MOVEMENT OF GOODS - QUANTITATIVE RESTRICTIONS - MEASURES HAVING EQUIVALENT EFFECT - CONCEPT ( EEC TREATY , ART . 30 ) 2 . FREE MOVEMENT OF GOODS - QUANTITATIVE RESTRICTIONS - MEASURES HAVING EQUIVALENT EFFECT - PRICING SYSTEMS - WHETHER PERMISSIBLE - CONDITIONS ( EEC TREATY , ART . 30 ) 3 . FREE MOVEMENT OF GOODS - QUANTITATIVE RESTRICTIONS - MEASURES HAVING EQUIVALENT EFFECT - PRICING SYSTEMS - LEGISLATION DIFFERENTIATED ACCORDING TO THE ORIGIN OF THE PRODUCTS - REFERENCE TO THE MANUFACTURER ' S BASIC PRICE FOR IMPORTED PRODUCTS - LEVEL OF PRICES OF DOMESTIC PRODUCTS FROZEN AT A REFERENCE DATE - NOT PERMISSIBLE ( EEC TREATY , ART . 30 )