The company may decide to issue shares in only one class or shares in several classes. A great number of articles will deal with the rationale for several classes over a single class, and vice versa. The number of share classes and their properties is a function of the needs of the company. Some companies will require a very simple structure, others for reasons including tax planning, or voting control, or mitigation of risk for investors will require more complicated share structuring. Also, within the number of authorized shares section of the articles of incorporation or articles of association, the company can set out the types of shares available for issue, and whether there is a limited or unlimited number of shares available. If the number of shares for issue is unlimited then the corporation isn't restricted by how many shares they can issue to new investors or employees. See authorized shares for more details on this item.