A Certificate of Origin or Declaration of Origin (often abbreviated to C/O, CO or DOO) is a document widely used in international trade transactions which attests that the product listed therein has met certain criteria to be considered as originating in a particular country. A certificate of origin / declaration of origin is generally prepared and completed by the exporter or the manufacturer, and may be subject to official certification by an authorized third party. It is often submitted to a customs authority of the importing country to justify the product's eligibility for entry and/or its entitlement to preferential treatment. Guidelines for issuance of Certificates of Origin by chambers of commerce globally are issued by the International Chamber of Commerce.