src/compatibility/4.0/versions.md

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# Permitted Version Strings for Android 4.0 #

As described in Section 3.2.2 of the [Android 4.0 Compatibility Definition](/cdds/android-4.0-cdd.pdf), 
only certain strings are allowable for the system property
`android.os.Build.VERSION.RELEASE`. The reason for this is that
applications and web sites may rely on predictable values for this string, and
so that end users can easily and reliably identify the version of Android
running on their devices.

Because subsequent releases of the Android software may revise this string,
but not change any API behavior, such releases may not be accompanied by a new
Compatibility Definition Document. This page lists the versions that are
allowable by an Android 4.0-based system. The only permitted values for
`android.os.Build.VERSION.RELEASE` for Android 4.0 are:

- 4.0

- 4.0.1

- 4.0.3