What is a Tagged PDF?
PDF 1.4 introduced "Tagged PDF".
A tagged PDF is a PDF document containing tags. It includes an underlying tag tree that provides assistive technologies with the structure of the PDF document. The structure helps interpret the content and the reading order of the document to users. Each tag identifies the type of content, and stores some attributes related to it.
Properly tagged PDF becomes accessible to everyone. An accessible PDF makes it easier for people with disabilities to access PDF documents with the aid of assistive technology software and devices (like screen magnifiers, screen readers, speech-recognition software, text-to-speech software, etc.). PDF/UA uses Tagged PDF to ensure electronic documents are fully accessible.
A PDF document can be tagged in two main ways:
- Manual tagging Manual tagging implies the use of software tools. Adobe Acrobat Pro is the best tool for tagging PDF documents.
- Auto-tagging Some software can automatically produce tagged PDFs, but this feature is not always enabled by default. Modern tools, such as Apple's office suite, automatically add tags when exporting to PDF.