Hierachical components
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I wanted to add a general caveat for anyone considering turning on this feature.
The reason we have it turned off in 6.0 is because all the functionality is not yet available from the Visual Studio client. If you have some team members who use the Eclipse client and others who use the Visual Studio client, and the Eclipse client users start introducing component hierarchy relationships, nothing will break, but there are certain operations that will not be available to the Visual Studio client users, so they may become frustrated.
If your team uses both clients and considers client feature parity important, this server side switch enables you to leave the feature turned off until full functionality is available in Visual Studio.
We are planning to update the Visual Studio with full functionality in an upcoming release.