The document discusses the rule for using commas between coordinating adjectives. It states that two or more adjectives that can be separated by "and" or "but" and independently modify a noun should be separated by commas. Examples are provided such as "Mr. Buckwalter lived in an old, dilapidated house" and "Mr. Buckwalter always helps little, old ladies cross the street." Practice rewriting sentences with coordinating adjectives and commas is also included.