The files contained in this folder are late additions to the SDK. They can be referenced from your code when you are making use of the following interfaces and their supporting enumerations and structures.

IBrowserService
IBrowserService2
IBrowserService3
IExpDispSupport
IShellService
ITravelEntry
ITravelLog

Documentation for these interfaces can be found at http://msdn.microsoft.com/library/. Note that these interfaces may not be supported in future versions of Microsoft Windows.