Multi-labelling for a thread - can a selected thread have two labels?

[Mithileysh]

Multi-labelling for a thread - can a selected thread have two labels? For example, let us say, I initially label a thread as "short discussion" and later want to label/mark it as "interesting". It is not possible currently, is it possible to do it?

[phongvis]

You can relabel a thread, but can't assign two labels. The classification is not fuzzy.