GAAR refers to a broad set of different types of rules aimed at limiting tax avoidance by multinational corporations in cases where abuse of tax rules has been detected. When used in tax treaties, GAARs can in some cases be used to prevent tax avoidance by allowing tax administrations to deny multinational corporations tax exemptions, but they do not address the general problem of lowering of withholding taxes through tax treaties, nor do they address the general division of taxing rights between nations (source).