What are Bookmarks in PDF

Bookmarks, also known as PDF's Document Outline feature, provide a convenient way to navigate through a PDF document. They serve as a table of contents or an interactive index that allows users to quickly jump to specific sections, pages, or points of interest within the document.

Bookmarks are commonly displayed in a separate navigation pane, making it easy for users to access different sections of a PDF without scrolling or searching extensively.

It is important to note that bookmarks are technically distinct from headings within the content of the document. While headings are part of the document's structure and help organize the content, bookmarks are an additional navigational aid that enhances the user experience.

The implementation and appearance of bookmarks may vary depending on the PDF viewer or editor being used. Users can typically expand or collapse bookmark levels, creating a hierarchical structure for easier navigation. By clicking on a bookmark, users are automatically taken to the corresponding section or page within the document.

For more detailed technical information about bookmarks, you can refer to clause 12.3.3 in ISO 32000-2:2020, the International Standard for the Portable Document Format (PDF). This standard provides comprehensive guidelines and specifications for PDF documents, including the definition and functionality of bookmarks.