PDF
…structure
and type, adding alternative text descriptions to non text elements, and
substitute text (referred to as actual text) for elements in the PDF document.”
Tags are used to indicate two things in a PDF:
• The existence of content
• The type of content (Heading, Paragraph, List, Table, Figure, etc.)
Most of the work necessary to remediate …
https://www.wichita.edu/services/mrc/Web_Services/_documents/PDF_Remediation.pdf