Both the MSF Agile and Scrum for Team System templates define the “Assigned To” list (“System.AssignedTo”) as:
The problem with that is that the list displays every user in your domain. I wanted to change that behavior since not every user in the domain uses TFS, plus we had some service accounts that didn’t need to get anything assigned to them, so this is how you would change it:
<LISTITEM value=“[Project]\Project Administrators“ />
<LISTITEM value=“[Project]\Contributors“ />
The list will contain all users in the current project’s “Project Administrators” and “Contributors” groups, excluding any group names. You can also make that change through the Power Tools Process Editor.