Using a Version Label in a WorkItem

Within the original workItem ChangeRequest that ships w/ MSF for CMMI Process Improvement there is a field:

<!-- **************** Build Integration Fields ******************************************* -->

<FIELD name="Integration Build" refname="Microsoft.VSTS.Build.IntegrationBuild" type="String" reportable="dimension">

<HELPTEXT>The build in which the change request was completed</HELPTEXT>

<SUGGESTEDVALUES>

<LISTITEM value="None"/>

</SUGGESTEDVALUES>

</FIELD>

This field allows you to select any Build Labels associated with the prjoect the workItem was created under. Any one know of or a similar field that would allow me to display a drop-down list of Labels from SourceControl?

<FIELD name="Test Version Label" refname="Microsoft.VSTS.VersionControl.Label" type="String">

<SUGGESTEDVALUES>

<LISTITEM value="None" />

</SUGGESTEDVALUES>

</FIELD>

I thought the above ref might work, but doesn't appear to be doing the trick. Curious if this is possible, do I have the refName wrong or what.

Thanks,
Kel