Markdown borrows most of its formatting conventions from writing documents in plain text. In the previous chapter, as part of an introduction to Markdown, we learned how to “underline” text with a row of equal signs to format them as major headings, or with a row of dashes to make subheadings. We also learned basic text formatting like two underscores or two asterisks for **bold** text or one underscore or one asterisk for _italic_ text.