According to PC World, the company has expanded its legal agreement with developers working on Android to specifically prohibit them from taking any action that could lead to a fragmentation of the operating system.
Google laid down the law in the fine print of its terms and conditions for Google's Android software development kit, which developers must accept before using the software to build apps.
The last version of the terms of service, which was released in 2009, did not bother to look at the problem. But the new one says developers are forbidden to take any action that could result in the fragmentation of Android.
This includes distributing, participating in "the creation of, or promoting in any way a software development kit derived from the SDK".
Android fragmentation become more important as the operating system has become popular. Most of the problems have come because of Google and the Android handset makers, rather than developers. But it has meant that Android applications may not run properly across all devices.
This means that Android version 4.2 can't run on some of the new Google-branded devices, handsets and tablets.