Although web sites and reporters often spill the secrets of companies, the best-kept ones get published by the companies themselves. Case in point is the revelation that 'folders' are coming to Update 1 (aka GDR1) for Windows Phone 8.1, which was accidentally revealed by Microsoft's website. Details though have been scarce about the forthcoming update, including what it contains. Luckily, Microsoft's Dev Center is filling in the blanks as we reported yesterday. On Microsoft's website, buried within the Dev Center are two pages dedicated to the minor OS update. One page is 'What's new in the documentation for Windows Phone 8.1 GDR1' and the other just 'Windows Phone 8.1 GDR1.' Now, details from those internal pages is starting to trickle out. Best VPN providers 2020: Learn about ExpressVPN, NordVPN & more

The information is for OEMs, who build Windows Phone hardware, and as such do not articulate too many consumer-facing features, but changes that are rather more technical. Still, there are quite a few things revealed hitherto unknown about GDR1, including: Support for 1280 x 800 WXGA resolution

Diagonal screen sizes of 6.01" to 7" are now supported for the 1280 x 768 WXGA resolution

540 x 960 native qHD resolution is now supported in addition to the ability to scale from HD or WVGA resolution to qHD

Diagonal screen sizes up to 6" and on phones that use the MSM8x12 applications processor now support 540 x 960 qHD resolution

Dual SIM – C + G radio type is now supported for dual SIM phones

Bluetooth – PAN (personal area network) 1.0 profile, aptX codec support for A2DP, and browsing support for AVRCP are now supported

Support for a Store live tile when the tile is medium-sized

The size of the Store tile has been standardized for all layouts and some tiles have changed places on the Start screen.

Support for folders.

Enable a phone cover app to launch when the phone cover is closed and specify the default setting for the lock screen's auto unlock setting.

Cortana – Add a phone book entry for Cortana to allow users to initiate speech from a car that doesn't have support for activating speech on the phone that is connected over Bluetooth.

Network Time Protocol support – Automatically set the time, using an NTP client, in a Windows Phone device that doesn't support NITZ or when cellular data is not available.

Voice over LTE (VoLTE) support

OEMs can implement a custom lock screen

OEMs can preload the Files app

Added a note that all Wi-Fi Sense settings must be on unless Microsoft executive approval has been granted for specific mobile operator requests. That is a massive (and only partial) list of changes coming to Windows Phone 8.1 GDR1. Many of those enable manufacturers' flexibility on making phones while others are sure to benefit consumers e.g. PAN 1.0 for Bluetooth, VoLTE support, and other minor adjustments like the medium Store tile. The 1280 x 800 resolution is for new higher end Windows Phones with software buttons, instead of the physical capacitive keys. Up until now, software keys were limited to 800 x 480 type displays. Interactive phone covers let manufactures develop cases for Windows Phones that when opened, unlock the display, enabling easier access to the phone. Likewise, when the phone case is closed, another action can be initiated with the configuration found under Settings. Android phones, specifically HTC's new One M8 already has a similar feature called the Dot View case.