Microsoft regulates the appearance of the Windows key logo picture with a specially crafted license for keyboard manufacturers ("Microsoft Windows Logo Key Logo License Agreement for Keyboard Manufacturers"). With the introduction of a new Microsoft Windows logo, first used with Windows XP, the agreement was updated to require that the new design be adopted for all keyboards manufactured after 1 September 2003.[5] However, with the release of Windows Vista, Microsoft published guidelines for a new Windows Logo key that incorporates the Windows logo recessed in a chamfered lowered circle with a contrast ratio of at least 3:1 with respect to background that the key is applied to.[6]