for this purpose they shall call for any necessary documentary( c) the reasons which have led to the decision . evidence or carry out any checjc which they consider appropriate .3. Where a decision on classification results in a change ofclassification practice or a change of category of any productsubject to the Agreement , the competent authorities of the Article 4Community shall provide 30 days' notice , from the date ofthe Community's communication , before the decision is put Where different criteria for determining origin are laid downinto effect . Products shipped before the date of application of for products falling within the same category , certificates orthe decision shall remain subject to the earlier classification declarations of origin shall contain a sufficiently detailedpractice , provided that the goods in question are presented description of the goods to enable the criterion to befor importation into the Community within 60 days of that determined on the basis of which the certificate was issued ordate . the declaration drawn up . Article 5 TITLE II The discovery of slight discrepancies between the statements ORIGIN made in the certificate of origin and those made in the documents produced to the customs office for the purpose of carrying out the formalities for importing the product shall