PARENTHESES

Use parentheses to enclose dates, references, or a group of words
which are only loosely connected with the sentence. Use
parentheses sparingly; they slow down the reader.

Punctuation marks go inside the parentheses when they apply to the
words enclosed in the parentheses.

        Both groups expressed an interest in western movies. (Your movie was shown
        three times.)

Punctuation marks that apply to the entire sentence go outside the
parentheses.

        The terms of the contract are outlined in Chapter 11 (page 20).

        They agreed to permit some military presence for a limited time (perhaps up to
        ten years), yet no final contract as signed.