TFS Power Tools - Undo Unchanged Command

Visual Studio Team System 2008 Team Foundation Server Power Tools contains an Undo Unchanged (UU) Command.

According to the site: "Use the UU (Undo Unchanged) command to undo unchanged files, including adds, edits, and deletes."

To use the UU command, you execute it from the command line:

C:\>Tfpt UU /recursive

You can find out more infromation on how to execute the UU command, or any TFPT command by typing help and then the command name, like:
C:\>TFPT help UU

The help menu displays the following information:

Some questions that I am looking for answers to:

1. How does it determine what changes are redundant?

2. Is there any way to preview the list?