undertake to inform of any changes in the Common Customs having been made in writing by the exporter or , under theTariff or NIMEXE before the date of their entry into effect in exporter's responsibility , by his authorized representative .the Community . The competent governmental authorities of Thailand shall ensure that the certificate of origin is properly completed and2. The competent authorities of the Community for this purpose they shall call for any necessary documentaryundertake to inform of any decisions relating to the evidence or carry out any check which they considerclassification of products subject to the Agreement within appropriate .one month of their adoption at the latest . Suchcommunication shall include :( a ) a description of the products concerned ; Article 4( b ) the relevant category , tariff position or sub-position and Where different criteria for determining origin are laid down the NIMEXE code ; for products falling within the same category , certificates or( c) the reasons which have led to the decision . declarations of origin shall contain a sufficiently detailed description of the goods to enable the criterion to be determined on the basis of which the certificate was issued or3. Where a decision on classification results in a change ofclassification practice or a change of category of any product the declaration drawn up .subject to the Agreement , the competent authorities of theCommunity shall provide 30 days' notice , from the date ofthe Community's communication , before the decision enters Article 5into effect . Products shipped before the date of entry intoeffect of the decision shall remain subject to the earlier The discovery of slight discrepancies between the statementsclassification practice , provided that the goods in question made in the certificate of origin and those made in the