If you're into knowing the deeper details about your device, then you've likely accessed the engineering screen on your BlackBerry before. Also known as the escreen, it offers access to many diagnostic tools and just a general wealth of information about how things are working on your device, under the hood so to speak.
Remote logs, Cell tower information, APN information, Wi-Fi state, Vendor ID and more can be accessed through this menu -- it's an insanely useful tool for those who know what to do with the information or understand what it all means. With BlackBerry 10, this menu was pretty much assumed to of have gone missing, due to the fact the old methods of accessing it no longer worked.
As it turns out, it didn't go missing at all. It's still there, still accessible -- it's just been hidden a little bit deeper in BlackBerry 10 than in previous OS versions. Thanks to @nerdtalker, @N301DQ and makaveli86 we now know how to do it and as such, are passing the info along.
The new method uses URL schemes so, in order to get things started you'll need to open your web browser and visit: escreen:// and then tap go.
Once loaded, visit this page and enter in the info needed, which is displayed after visiting the above URL - Device PIN, OS Version, and uptime. Duration can be set to whatever you wish from the available options. If set to 30 days, you won't need to repeat the process for 30 days etc.
Once the info is entered, a code will be generated. From there, two-finger swipe up to raise the keyboard and then input the code as shown. No new screen or box will show for the input, just enter the code. No text input box will appear, so you're typing it blindly and it's not case sensitive. The escreen will then change, offering you access.
It should go without saying that you shouldn't really access this page unless you know what you're looking for or doing but overall, I don't think much harm can come from it. If it's anything like BBOS, all changes you make should revert after a reboot but alas, that remains untested. In short, if you don't what you're doing in here then it's best to NOT change anything or even access it. If you like to tinker around though, then have it and let us know if anything cool comes out of it. Be sure to say thanks to @nerdtalker, @N301DQ and makaveli86 as well, if you've been waiting for this to be uncovered.