A block quotation (also known as a lengthy quotation or extract) is a quotation in a written document that is separated from the main text by a paragraph or block of text and is generally identified visually by indentation and a distinct typeface or font size. Block quotations are often used to highlight important phrases or sections within a larger work. Set off quotations are quotations that have been taken out of their original context and presented in isolation. Such quotations need to be cited with a reference, which alerts readers to the fact that they are not part of the main text. Set off quotations can be used to highlight important ideas in a passage without disrupting the flow of the text. They are also useful for including quotes within quotes. For example, a writer might use set off quotations to indicate when a quote begins and ends independently within its parent sentence or line. Set off quotations can also be used to provide emphasis by placing them in different positions in the text. A set off quotation at the beginning of a paragraph may for example, indicate that what follows is an extended version of the topic covered in the quoted material. Finally, set off quotations can be used to avoid plagiarism. If someone else's work is being quoted extensively but not attributed, then this would be considered academic misconduct. The use of set off quotations allows the author to include these works without being accused of copyright infringement.