Microsoft has confirmed that it will release the Windows Phone 8.1 Update 2 or, GDR 2 but only to select Lumia models.

The company made the announcement at the launch event of Lumia 640 and Lumia 640 XL in the UK. Microsoft's affordable Lumia series including Lumia 830 and Lumia 735 are among the lucky ones to receive the update, but only in certain markets and carriers, reports Neowin.

The update will address the new US legislation with regards to anti-theft protection for mobile devices. This does not mean that all Lumia models will get the Update 2. The upgrade for a particular device will be made on a case-by-case basis.

Unlike the Windows Phone 8.1 Update 2, the company's primary focus is on completing the Update 1, which brings the Lumia Denim features. At present Lumia 640 and 640 XL are the only two devices which offer access to Update 2.

Reset Protection:

Microsoft has recently introduced a feature in Windows Phone 8.1 Update 2 called 'Reset Protection', which helps to secure a device in case it is stolen. Given below are the features of Reset Protection.

Reset and reactivation protection – The stolen device cannot be reused by resetting or flashing the device. When users perform a factory reset on the device, they will be asked to enter the Microsoft Account credentials that are associated with that device. Additionally, if the device is flashed with a new image and Reset Protection is turned on, the Microsoft Account credentials that were associated with that device is required to finish OOBE and use the device.

Anti-rollback protection – If Reset Protection is enabled, the stolen device cannot be flashed to an earlier version of the operating system that did not support Reset Protection.

More information about Reset Protection is available at Windows Phone Dev Center.