Two months ago, Microsoft began migrating Dev Center accounts to the new unified dashboard, offering several new improvements to the Windows Phone and Windows Dev Center dashboards. One of these changes includes the way age ratings are handled for app submissions. In the new unified Dev Center dashboard, every new app and game (including new app and game updates) will require a Windows Store age rating. This was previous required for Windows apps but was not available for Windows Phone apps.
The idea behind this is to streamline and simplify app submissions with age ratings and to help customers easily identify the age-appropriateness of an app. Developers, all you have to do is select App properties during the Dev Center app submission process, and choose one of five Windows Store age rating categories: 3+ (suitable for young children), 7+ (suitable for ages 7 and older), 12+ (suitable for ages 12 and older), 16+ (suitable for ages 16 and older), and 18+ (suitable for adults). Developers can also set market=specific age ratings, such as ESRB, CSRR, GRAC, and more, all within the Dev Center dashboard.Further reading: Microsoft, Windows 8.1, Windows Phone, Windows Store