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Acrobat Chapter 1: Introduction

Acrobat Chapter 1: Introduction

 Instructions

Section 1.1: What are Tags?

Tags are invisible labels that help identify document elements, making them essential for assistive technologies like screen readers. These tools rely on tags to determine if an element is text, an image, or a table. Without tagging, screen readers can't interpret the document's structure.

Tags provide semantic organization, allowing screen readers to convey the document’s layout to users. Sighted users can visually scan headings, but screen reader users need properly tagged headings to navigate efficiently.

Tagging a PDF is crucial for accessibility. If you know HTML, PDF tagging will be familiar; if not, some practice will help you understand it.

Types of Tags in Acrobat:

  • Article

  • Annotation

  • Bibliography

  • Block Quote

  • Caption

  • Code

  • Division

  • Document

  • Figure

  • Form

  • Formula

  • Heading

  • Heading Level 1-6

  • Index

  • Label

  • Link

  • List

  • List Item

  • List Item Body

  • Note

  • Paragraph

  • Part

  • Quote

  • Reference

  • Section

  • Span

  • Table

  • Table Data Cell

  • Table Header Cell

  • Table of Contents

  • Table of Contents Item

  • Table Row

Section 1.2: Remediation Flow in PDF Documents

There are several different ways to work on a PDF, but you have to know which pipeline to use. If you have access to a source document, you need to follow these steps to make it accessible.

If you have the original source document:

  1. Optimize the original Source Document for accessibility

  2. Convert the Source Document into a Tagged PDF

  3. Add Metadata

  4. Add/Fix Tags as needed

  5. Improve the Reading Order & Tab Order

  6. Check the accessibility of your work

    The process to remediate a PDF when you start with the original source document.

If you need to work with a poorly tagged PDF:

  1. Add Metadata

  2. Add/Fix Tags as needed

  3. Improve the Reading Order & Tab Order

  4. Check the accessibility of your work

    The process to remediate a PDF when you start with a poorly tagged PDF.

If the tags are in very bad shape, you might find it easier simply to delete them all and start tagging from scratch.

If you need to start with an untagged PDF:

  1. Add Metadata

  2. Autotag Simple Documents/Manually Tag Complex Documents

  3. Add/Fix the tags as needed

  4. Improve the Reading Order & Tab Order

  5. Check the accessibility of your work

    The process to remediate a PDF when you start with an untagged PDF.

If starting with a paper or scanned document:

  1. Scan the document, if needed.

  2. Use Optical Character Recognition (OCR) Tool to generate searchable text.

  3. Add Metadata

  4. Add/Fix Tags (Automatically/Manually)

  5. Improve the Reading & Tab Order

  6. Check the accessibility of your work

    The six steps for making a scanned document accessible.

Section 1.3: PDF Accessibility Standards

WCAG (Web Content Accessibility Guidelines) provide rules for making web content accessible with 78 clear, measurable criteria that pass or fail. For example, text must have be above a certain size to be accessible—if it’s too small, it fails. WCAG defines technical requirements (success criteria), methods to meet them, and additional guidance.

PDF/UA (PDF/Universal Accessibility) is the standard for making PDFs accessible, also known as ISO 14289. Based on WCAG 2.0, it sets specific criteria for accessibility. To support this, the Matterhorn Protocol was created, outlining 31 checkpoints with 136 failure conditions to help developers and document authors follow PDF/UA.

WCAG and PDF/UA are similar, with some differences, but both aim to ensure an accessible user experience. Both are published by the International Organization for Standardization (ISO).

Yes, WCAG applies to PDFs, even though it only mentions them once. When a PDF is shared online, it becomes web content, so WCAG standards apply. However, WCAG is mainly designed for websites, making it challenging to interpret for documents like PDFs.

The W3C Working Group has provided techniques for meeting WCAG using different technologies, including PDF. It's important to note that these techniques are informative. This means they offer guidance, but they are not normative. They do not establish mandatory requirements for WCAG compliance. To learn more, visit the Techniques for WCAG 2.2.

Authors often find it challenging to navigate the overlapping requirements of WCAG and PDF/UA. To simplify this, a team of experts created a mapping of WCAG 2.0 guidelines to their corresponding PDF/UA standards. This effort resulted in a detailed guide called Achieving WCAG 2.0 with PDF/UA, published by AIIM (The Association for Information and Image Management), the ISO’s governing body. The guide provides clear steps for achieving WCAG 2.0 compliance using PDF/UA. However, it only covers WCAG 2.0 and does not include the 17 new success criteria introduced in WCAG 2.1.

WCAG and PDF/UA work well together, and using both ensures the creation of highly accessible PDF documents.

This course will focus on WCAG compliance.

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