Quotation marks Use double quotation marks to introduce a word or phrase used as slang, or as an invented or coined expression. Use quotation marks only the first time such a phrase is used. Do not use double quotation marks to apologize for using an expression in a sarcastic way, as if it means the opposite of what it does. Place periods and commas within the closing double quotation marks. Other punctuation, unless it is part of the original quotation, follows the closing quotation marks.
Brackets Use square brackets to introduce an acronym.
Colon Use a colon to call attention to the words that follow it. Leave one typed space after a colon. It is traditional to leave two typed spaces after the period at the end of the sentence. In documents that have been word-processed, one space after the final period is preferred. However, both are correct.