FAQ #7: Can I combine a list of valid TFS users and a fixed list to present as an option for an "Assigned To" field?
This question came in on an internal alias.
The answer from Naren Datha:
<ALLOWEDVALUES expanditems="true" filteritems="excludegroups">
<LISTITEM value="Active" />
<LISTITEM value="Closed" />
<LISTITEM value="[project]\Contributors" />
<LISTITEM value="MsftConn" />
<LISTITEM value="[project]\Test Vendor Contributors" />
<LISTITEM value="[project]\Test Vendor Readers" />
</ALLOWEDVALUES>