What is used to enclosed numbers or letters in a series?

Answer 1

A pair of parentheses is used to "enclose" numbers or letters in a series or elsewhere when enclosure is useful to understand the meaning. However, to separate the items in a series, only a comma and space after each item is needed, along with a conjunction to close the series. Examples: 1, 1, 2, and 3 are the first four numbers of a Fibonacci series; paragraphs (A), (B)(2), and (D) are the most relevant ones for this discussion.