New in version 3.1.

When Cross Compiling for Android with NVIDIA Nsight Tegra Visual Studio Edition, this variable may be set to specify the default value for the ANDROID_API target property. See that target property for additional information.

When Cross Compiling for Android, the CMAKE_SYSTEM_VERSION variable represents the Android API version number targeted. For historical reasons, if a toolchain file sets CMAKE_ANDROID_API, but not CMAKE_SYSTEM_VERSION, the latter will be initialized using the former.