Accomplishments over the last ten years include the liberation of trade among GCC member states through tax exemption on all agricultural, livestock, industrial and natural wealth products; permission for GCC citizens to practice wholesale and retail trade in any state, to own stocks, and to freely practice the professions of accounting and engineering; the opening of consulting offices and the issue of a number of consultative commercial regulations; the establishment of a commercial arbitration center; and accreditation of a standard system for accountancy and auditing.