The following build has /AppleInternal, but is not just another SwitchBoard build. In fact, it's a GUI build with extra applications and other internal stuff made just for testing cellular functions. It is currently believed that these are used to test cellular functionality and carrier related things, thus the name CarrierOS.
Unlike normal factory builds, this one does not have any mach_development files in the root directory, further pushing the belief that this is only to test cellular related functions and nothing more. There are also only three AppleInternal applications that come with CarrierOS, as well as seemingly normal Applications in /Applications, which are normally not present in typical Factory Firmwares.
Upon booting into the OS, you should get a seemingly normal stock 10.2.1, but with three extra apps. They go as follows:
Other Anomalies[edit source]
Unlike most Factory builds, this one is only compatible with the iPhone 6 (n61). This is evident because it only comes with one kernelcache, as well as firmware for the iPhone 6 only. It does, however, come with a debug baseband firmware and plist. It also comes with Carrier Settings.bundle, as well as many other internal libraries.