The way Q used the brackets in his post today: [J-Go_dx)-2-8 stood out

Here is some reference for bracket usage:

generally, the term brackets are used for square brackets. In mathematics, it is used for interval notation used for expressing the domain and range of functions. Parenthesis (single one) is used if the point is not being included in the interval, whereas a bracket is used when the point is included.

For example - (5, 6] - This means that 5 is excluded and 6 is included in this interval.

http:// www.differencebetween.info/difference-between-brackets-and-parentheses