When you play Blaster Master, you start to notice that a lot of the powerups have letters on them that roughly correspond to what they do: pickups that increase your Power have a P on them, pickups that increase your Hover meter have an H on them, homing missiles also have an H on them, et cetera. But one of the ones that always perplexed me was the powerup for your gun in the overhead scenes. It had a little F on it for some reason.
I figured it was maybe some kind of translation error and never really thought about it too much it. At least not until years later when I realized that there's no 'F' on it at all, it's just a picture of a six-shooter, and what I thought was an 'F' was actually the highlights around the gun itself. There's even a handle and a barrel, and a trigger, and all of the other stuff that I mentally just completely disregarded when I thought that the developers didn't know how to spell 'gun' correctly.