A [search](http://superuser.com/search?q=is%3Aq+%22Bulk+Rename+Utility%22) turns up only seven questions that mention the Bulk Rename Utility, and out of those, only two or three are actually *about* the tool. The BRU doesn't seem widespread or nuanced enough to merit a tag considering the previous.

Therefore, I don't think we need a tag for it yet. Tag such questions with the OS and what you're trying to accomplish. Mention the specific software and its version in the question too, of course.