Why bracket? The reason is that there is not only ket vectors |v> but also functionals <u| that can be applied to them, which will look like this <u|v>. So there are brackets around the construct. Think <bra|ket> if you like.
Clearly OT but the excessive reliance on foo and bar in many of my early C lang learning examples really slowed down my ability to transfer said techniques into something meaningful. Eventually one of my friends working in the Visual C++ team (I'm dating myself here) explained the connection of foo and bar to fubar and kind of felt like this!
I had the same experience; that's mostly what I'm referencing. Trying to use things like The Hacker's Dictionary (largely in-jokes, bad jargon, and obnoxious circular definitions) to clear it up made the problem worse. I get that it's just a humor book, but still.
it is strange that you have such a charming notion about the flavours of quarks. If we turn this notion upside down maybe we could then get to the bottom of this or should i say the top?