The word "sic" is often used in writing, especially in the context of quoting someone or something exactly as it appears, including any errors or unusual language. It indicates that the text is being presented faithfully, as it was found, and not altered or corrected by the person quoting it. This is used to reassure readers that the original source contained the quoted material that way.
The term "sic" comes from Latin, where it means "thus" or "so." It has been used in English since the late 19th century to indicate that a quoted text is being presented exactly as it was found, with any flaws intact.