Words in matrix overlays?

[HLidstrom]

I know how to make an overlay with the UML Type editor, e.g. defining R, A, C, I for a RACI matrix. But is it possible to have a set of words instead of a set of characters? (E.g., Responsible, Accountable, Consulted, Informed.)

I can enter a comma-separated list of words when I define an overlay, but then every character of every word in the list will be accepted when I apply it in the matrix. Am I doing it wrong, or is it just not possible?
I am using Sparx EA 14.
Thanks!
- Håkan