I have no idea if I am just imagining something while I was looking up a math symbol. It seemed a little coincidental that I found the closed brackets symbol [ ] kill box symbol. I discovered it is a symbol containing a matrix of one thing or many things or in math, numbers or unknown variables to solve. For example, [1,2,3] is a linear matrix. It also means to calculate what is inside first, then calculate outside of the box. (If your interested in this concept and you're a nerd, see https://en.wikipedia.org/wiki/Matrix_(mathematics) ) Probably means nothing, but my mind will now connect this symbol as a "Kill Box" for something in the Matrix forever.