“language” attribute on patterns?

Our cases have a “group / workshop” attribute. This is because we collect them from various communities, and the participants in these communities want to quickly find their peer’s contributions. We didn’t have a similar attribute for patterns, thinking that the whole point of patterns is to promote generality and knowledge transfer. Now, that is still true, yet on the other hand we can see several distinguishable (if not distinct) languages emerging. Patterns for e-Assessment are a cluster apart from HCI patterns etc. After all, this is the pattern language network.
So, should we add a “language” attribute to patterns? Should it be single or multiple choice?