Microsoft released minimum hardware requirements for tablet and laplet devices to be "certified" for Windows 8, and defined a convertible form factor as a standalone device that combines the PC, display and rechargeable power source with a mechanically attached keyboard and pointing device in a single chassis. A convertible can be transformed into a tablet where the attached input devices are hidden or removed leaving the display as the only input mechanism. On March 12, 2013, Microsoft amended its certification requirements to only require that screens on tablets have a minimum resolution of 1024×768 (down from the previous 1366×768). The amended requirement is intended to allow "greater design flexibility" for future products.

What did Microsoft change the tablet resolution requirements on March 12, 2013?