@Jonas Staggs
BFS = bait finesse system - it's a reel, it's a baitcast reel made to fish light lines and cast light weights.
Since the Japanese coined the term, it's only fair for them to define it.
What makes it a system is the shallow lightweight spool, low-inertia bearings, and brake system tuned to cast light lures, and even better, an extreme lure weight range.
The rods cover a dozen niches, from stream to offshore XUL jigging - bass are in there, also, and so is shore light game.
The trout rods are going to come closest to traditional American UL - short rods with narrow lure weight range and para taper. If I take it to the copystand, I can give you great example Harnell UL rods from my 1960 catalog.
I fish bass and shore light game (inshore), and having rods designated to cast 2 to 20 g and protect light lines, it's nice to have a BFS reel that can match those ranges.
Every shore has its threadlining tradition, XUL, finesse, progressive taper rods based on fly rod tapers. The rods are capable of an extreme lure weight range, light tip, fast mid and stout butt for turning big fish - the reels to match them should be capable of the same extreme lure weight range. The tradition is certainly spinning reels (Atlantic salmon in Scotland), but now we have baitcasters capable of the same and even better - BFS - bait (baitcast reel) finesse system.
That said, I have a prewar baitcaster designed and capable of fishing 1/8 oz.
You can call this threadlining, XUL, finesse spinning, shore light game, but you can't call it BFS, because it uses a spinning reel and not a BFS reel.