What punctuation is used to enclose numbers or letters in a series?

The punctuation used to enclose numbers or letters in a series depends on the style guide you're following.

Here are the most common options:

* Parentheses: (1) This is the most common option, particularly in formal writing.

* Brackets: [1] This is less common than parentheses, but it's acceptable.

* No punctuation: 1 This is a simpler option, but it can be less clear in a long list.

For example, here are three ways to write a series of points:

* (1) This is the first point.

* (2) This is the second point.

* (3) This is the third point.

* [1] This is the first point.

* [2] This is the second point.

* [3] This is the third point.

* 1 This is the first point.

* 2 This is the second point.

* 3 This is the third point.

Ultimately, the best option depends on your personal preference and the specific guidelines of your writing.