Any two or more boards of library trustees acting as incorporators under this section and the nonstock corporation laws may organize a cooperative library corporation to administer joint library projects in their counties. The membership of the corporation consists of the members of each board of library trustees that signs the articles of incorporation. If each of the member boards agree, another county may become a member of the corporation. The member boards may delegate any of their intracounty powers and duties to the corporation to the extent necessary to enable it to carry out and administer joint library projects. Professional and clerical employees of a cooperative library corporation shall join the Teachers’ Retirement System. Each cooperative library corporation: Is entitled to use the library fund; Shall have the annual audit required for a library; Shall make the annual report required of a board of library trustees; and Is exempt from taxation under § 7-202 of the Tax - Property Article.