We are running TFS 2015.2. Am I not able to use the MultiValue Control with a Global List configured for the Suggested Values? Or, is my issue that the total characters for all items on the Global List exceeds a total of 255 characters? After adding to my User Story WIT, and I try to open an New User Story, I get message saying:

<MyField> does not have any values to list int he multiple value control. See "Work Item Tracking Multiple Value Control.doc" for details on defining a field to support multiple value control.

Can't seem to find the .doc referenced anywhere, as a side note.

I want to use a global list of our customers, to show which (more than one in some cases) requested the enhancement or bug fix.