In the documentation for the <securityTokenHandlers> element (http://msdn.microsoft.com/en-us/library/hh568671.aspx), it is stated that the "name" attribute can be used to specify SecurityTokenHandler types for the ActAs and OnBehalfOf collections. In practice, however, this does not work.
Visual Studio/Team Foundation Server/.NET Framework Tooling Version
Steps to reproduce
Operating System Language