Can't search for version number string - vBulletin limitation?

With multiple versions of the product covered in the forum, it’s a real handicap to not be able to search by a version number, e.g. ‘6.7’. Judging from google results on the topic, this is a limitation of vBulletin not providing very good search.

With a forum this size, effective search is essential to avoid wasting time reviewing many forum posts that turn out to be unrelated to one’s problem.