According to PDF/UA standards, what must be true of all meaningful content?

The assertion that all meaningful content must be tagged and integrated into the document's structure is central to the PDF/UA (PDF Universal Accessibility) standards. Tagging ensures that assistive technologies—such as screen readers—can accurately interpret the content and convey it to users with disabilities in a logical and usable format. This structural integration facilitates navigation, reading order, and context, making it easier for users to comprehend the information presented.

Meaningful content includes not just text but also elements like images, tables, and lists, all of which should have appropriate tags to ensure they are accessible. The need for a well-structured document aligns with the principles of universal accessibility, allowing all users, regardless of their abilities, to access and interact with the document effectively.

Content that is visually appealing, editable by users, or omitted in simplified versions may have their own merits but do not align with the fundamental requirements of making meaningful content accessible as per PDF/UA standards.