What needs to be inserted to reference a page number from another location in the document?

To reference a page number from another location in the document, a bookmark is essential. A bookmark allows you to create a link to a specific part of your document. This feature is particularly useful when you want to navigate easily or reference information within extensive documents. When you insert a bookmark at the desired location, you can then create a cross-reference or hyperlink that points to this bookmark, thereby allowing users to click and jump directly to that page number or section.

In contrast, footnotes are primarily used for providing additional information or citations at the bottom of the page, while a table of contents helps organize and provide an overview of sections and page numbers but does not reference specific page numbers directly from other parts of the document. A header typically contains repeating information such as the document title or chapter name across the top of the pages and doesn't serve the function of linking to specific locations within the content.