Engineer Fag here. Took an automatic controls course sometime in undergrad. This is the only place I have experienced [closed brackets] and ]open brackets[. Specifically in the process of finding root locus of a system with a feedback control to determine the stability of a system weather it be an air conditioner or flight stability of a fighter jet. I failed a quiz because of not knowing the difference between the brackets. Our answers would be in the terms of [1,8] where it meant that the any number between 1 and 8 including those numbers would produce the result needed. When it was ]1,8[ the answer would be any number between 1 and 8 but not including those numbers. You could also have a combination of brackets such as ]1,8] or [1,8[.

TLDR:

[] closed brackets=included

][ open brackets= excluded

]Sessions[= excluding Sessions?