Re: what is bb_topic_labels()?
In plain english it essentially replaces the need for things like “Sticky:” to be hard coded into templates. Long overdue but at least it got put in there finally.
However when making templates for backwards compatibility, you’d have to detect if that function exists before relying on it.
The only themes I’ve seen that uses it already outside of the built-in default is “K2 for bbPress” (and now my “FutureKind”).
It allows tricks like I’ve done to replace “sticky” with a post-it-note-like yellow rectangle. But it also could be filtered via plugin to change it to a little graphic icon, etc. which was impossible before the function existed.