Sorry, my edit wasn't precise. I understand the ":2" I just don't see it documented anywhere, aside from the example in this thread. A :# can be appended to tracknr, so I'll assume it can be used as a modifier for other numerical tags. What other undocumented (or, more likely, documented in a place I haven't yet found) modifiers exist? Is there one that turns spaces into underscores? Or is that an option under preferences?