Checkpoint 19: Notes and References

Footnotes, endnotes, and references must be properly tagged to maintain the relationship between reference marks in the text and their corresponding notes. This includes using Note and Reference tags with unique identifiers.

What This Means

Academic, legal, and technical documents frequently use footnotes, endnotes, and references to provide additional information, citations, or clarifications. PDF/UA requires specific tagging for these elements:

• Note tag: Used for footnotes, endnotes, and similar annotations
• Reference tag: Used for in-text citations and reference marks
• ID attribute: A unique identifier on each Note tag
• Link relationship: Reference marks should link to their corresponding notes

The structure allows assistive technology to:

1. Identify when the reader encounters a reference mark
2. Navigate to the corresponding note
3. Return to the original position in the text
4. Distinguish notes from regular content

Without proper tagging, footnotes become disconnected blocks of text that users cannot relate to their reference points in the main content.

Why It Matters

Notes and references are fundamental to scholarly and professional documents:

• Academic papers: Citations, explanatory footnotes, bibliographic references
• Legal documents: Case citations, statutory references, clarifying notes
• Technical documentation: Source references, additional details, clarifications
• Financial reports: Accounting notes, methodology explanations

For users of assistive technology, improperly tagged notes create significant problems:

• Lost context: Users cannot connect note content to its reference point
• Navigation difficulties: No way to jump between reference and note
• Confusion: Notes appear as random text blocks without clear purpose
• Missing information: Users may not realize notes exist at all

Consider a legal brief with 50 footnotes. Without proper tagging, a screen reader user would encounter footnotes as disconnected paragraphs at the bottom of pages, with no indication of what text they relate to.

Common Violations

The Matterhorn Protocol defines four failure conditions for notes and references. Two require human testing, and two are machine testable.

19-001: Notes Not Tagged as Note (Human Testing)

What's Wrong: Footnotes, endnotes, or similar annotations are not tagged with the Note tag. They may be tagged as paragraphs, figure captions, or other inappropriate structures.

How to Identify:

• Locate footnotes and endnotes in the document
• Check the Tags panel for how these are tagged
• Notes should use the Note tag type
• Look for footnote content tagged as P, Span, or other tags

Common Scenarios:

• Footnotes at page bottoms tagged as regular paragraphs
• Endnotes in a section tagged as a list or paragraphs
• Marginal notes tagged as figures
• Comment annotations not using Note structure

19-002: References Not Tagged as Reference (Human Testing)

What's Wrong: Reference marks in the text (like superscript numbers or citation brackets) are not tagged with the Reference tag. They may be tagged as regular text or links without proper semantic identification.

How to Identify:

• Find reference marks in the main text (e.g., "¹" or "[1]" or "(Smith, 2024)")
• Check Tags panel for these elements
• Should be tagged as Reference (or linked reference structure)
• Look for reference marks tagged as Span, P, or inline content

Common Scenarios:

• Superscript footnote numbers tagged as regular text
• Citation brackets tagged as paragraph content
• Bibliography reference numbers not using Reference tags
• In-text citations without semantic markup

19-003: Note Tag Missing ID Key (Machine Testable)

What's Wrong: A Note tag exists but does not include an ID attribute. The ID is required to uniquely identify the note and enable linking from reference marks.

How to Identify:

• PDF/UA validators will flag this automatically
• In Acrobat, check Note tag properties for ID attribute
• Missing ID means references cannot properly link to notes

Technical Requirement: Each Note tag must have a unique ID in its attributes, such as:

<Note ID="footnote-1">
  Content of the footnote...
</Note>

19-004: Note Tag ID Is Non-Unique (Machine Testable)

What's Wrong: Multiple Note tags share the same ID value. IDs must be unique within the document to properly identify each note and support linking.

How to Identify:

• PDF/UA validators check for duplicate IDs
• Review all Note tags and their ID values
• Each ID must appear only once in the document

Example of violation:

<Note ID="note-1">First footnote</Note>
<Note ID="note-1">Second footnote</Note>  <!-- Duplicate ID! -->

How to Fix in Adobe Acrobat

Creating Note Tags

1. Open View > Show/Hide > Navigation Panes > Tags
2. Locate footnote content in the tag structure
3. If not tagged as Note:
   • Right-click the tag > Properties
   • Change Type to Note
4. If untagged, use Reading Order tool:
   • Go to Tools > Accessibility > Reading Order
   • Select the footnote content
   • There is no direct Note button, so first tag as text, then change type

Adding ID Attributes to Notes

1. In the Tags panel, select a Note tag
2. Right-click > Properties
3. Click the Tag tab
4. Click Edit Attribute Objects
5. Add a new attribute:
   • Key: ID
   • Value: A unique identifier (e.g., "fn1", "footnote-1", "note-section2-1")
6. Click OK

ID naming conventions:

• Use consistent prefixes: "fn-", "note-", "endnote-"
• Include sequential numbers: "fn-1", "fn-2", "fn-3"
• For complex documents, include section: "ch2-fn-1"
• Ensure uniqueness across the entire document

Creating Reference Tags

1. Find the reference mark in the tag structure
2. It may be inside a P tag or Span
3. Right-click > Properties
4. Change Type to Reference
5. Ensure the reference is linked to its note (see linking below)

Linking References to Notes

For full accessibility, references should link to their notes:

1. The Reference element should contain or be associated with a Link
2. The Link's destination should point to the Note's ID
3. This enables "click to jump" functionality

Manual link creation:

1. Go to Tools > Edit PDF > Link > Add or Edit
2. Draw a link box around the reference mark
3. Set the destination to the note location
4. Ensure the link is properly tagged within the Reference structure

Verifying Unique IDs

1. Use Tools > Print Production > Preflight
2. Run a PDF/UA validation profile
3. Check for duplicate ID errors
4. Fix any duplicates by changing ID values

Handling Endnotes Sections

For documents with collected endnotes:

1. Tag the entire endnotes section appropriately (Sect or Part)
2. Tag each individual endnote as Note with unique ID
3. Ensure reference marks in the text link to the endnotes
4. Consider adding a heading for the Endnotes section

How to Fix in Microsoft Word

Using Word's Footnote Feature

1. Place cursor where reference mark should appear
2. Go to References > Insert Footnote (or Ctrl+Alt+F)
3. Word creates linked footnote/reference pair
4. Type the footnote content
5. The structure is preserved when exporting to PDF

Using Word's Endnote Feature

1. Place cursor at the reference point
2. Go to References > Insert Endnote (or Ctrl+Alt+D)
3. Word creates an endnote with linked reference
4. Endnotes collect at document end by default
5. PDF export maintains the structure

Managing Footnotes and Endnotes

1. Double-click any footnote reference to jump to the note
2. Double-click in the footnote area to return to reference
3. This bidirectional linking exports to PDF

Converting Between Footnotes and Endnotes

1. Right-click on a footnote
2. Select Convert to Endnote (or vice versa)
3. Word maintains proper linking

Custom Reference Marks

If using non-standard reference marks:

1. Go to References > Footnote Dialog launcher (small arrow)
2. Under Custom mark, enter your preferred symbol
3. Or choose from Number format options

Verifying Before Export

1. Review all footnotes and endnotes in Word
2. Click each reference to ensure it links correctly
3. Export to PDF with accessibility enabled:
   • File > Save As > PDF
   • Click Options > Create bookmarks using: Headings
   • Ensure Document structure tags for accessibility is checked

Post-Export Verification

1. Open the PDF in Acrobat
2. Check that footnotes are tagged as Note
3. Verify references are tagged as Reference
4. Confirm IDs are present and unique
5. Test links between references and notes

Testing Your Fix

Automated Testing

PAC (PDF Accessibility Checker):

1. Open the PDF in PAC
2. Run PDF/UA validation
3. Check for Note and Reference checkpoint failures
4. Review any ID-related errors

Adobe Acrobat:

1. Go to Tools > Accessibility > Accessibility Check
2. Run with PDF/UA settings
3. Look for structure-related issues
4. Note: May not catch all note/reference issues

Manual Structure Review

1. Open the Tags panel
2. Search for all Note tags:
   • Verify each footnote/endnote is tagged as Note
   • Check that each Note has an ID attribute
   • Verify all IDs are unique
3. Search for Reference tags:
   • Verify each reference mark is tagged as Reference
   • Check for proper linking to Notes

Screen Reader Testing

1. Open PDF with NVDA, JAWS, or VoiceOver
2. Navigate through the document
3. When encountering reference marks:
   • Screen reader should identify as reference/footnote
   • User should be able to follow to note
   • User should be able to return to reading position
4. When in footnote area:
   • Notes should be clearly identified
   • Content should be readable in context

Link Functionality Test

1. Click on a reference mark in the text
2. Verify it jumps to the corresponding note
3. Check for a "return" mechanism
4. Test several references throughout the document
5. Verify endnote links work from any page

Validation Checklist

• All footnotes are tagged as Note
• All endnotes are tagged as Note
• All reference marks are tagged as Reference
• Every Note tag has an ID attribute
• All Note IDs are unique
• References link to their corresponding Notes
• Screen reader properly announces references
• Navigation between reference and note works
• Note content is readable and in logical order

Different Note Types

Footnotes

• Appear at the bottom of the page
• Typically numbered sequentially per page or per document
• Used for citations, clarifications, asides

Structure:

Main text with <Reference>¹</Reference>
...
<Note ID="fn-1">
  ¹ Source citation or additional information.
</Note>

Endnotes

• Collected at the end of a document or section
• Often numbered continuously throughout document
• Used in academic and legal writing

Structure:

Document body with <Reference>¹</Reference>, <Reference>²</Reference>
...
Endnotes Section
<Note ID="en-1">1. First endnote content.</Note>
<Note ID="en-2">2. Second endnote content.</Note>

Margin Notes

• Text in page margins
• Less common in PDFs
• Should still use Note tag if providing supplementary information

Author-Date Citations

• In-text citations like (Smith, 2024)
• Reference mark links to full citation in bibliography
• Use Reference tag for the in-text citation

Structure:

According to research <Reference>(Smith, 2024)</Reference>...
...
References
<Note ID="ref-smith-2024">Smith, J. (2024). Title. Publisher.</Note>

Common Patterns for Complex Documents

Legal Documents

Legal briefs often have extensive footnotes:

• Number footnotes sequentially throughout
• Include case citations, statutory references
• May have both footnotes and a table of authorities

Academic Papers

Scholarly articles may use:

• Footnotes for explanatory notes
• Endnotes for citations
• Bibliography/References section
• All should be properly linked

Technical Manuals

Technical documentation might include:

• Footnotes for caveats and warnings
• References to other sections
• Cross-references to external standards
• Use Note for explanatory content, Reference for cross-refs

Additional Resources

Official Standards and Guidelines

• W3C WCAG 2.1 Success Criterion 1.3.1: Info and Relationships
• PDF Association Matterhorn Protocol 1.02
• PDF/UA Technical Implementation Guide

Document Structure

• PDF Reference: Note Structure Element
• WebAIM: Semantic Structure
• Microsoft Word: Insert footnotes and endnotes

Tools

• PAC (PDF Accessibility Checker) - Free PDF/UA validation
• NVDA Screen Reader - Free screen reader for testing
• CommonLook PDF Validator - Professional PDF validation

This documentation is based on the Matterhorn Protocol 1.02, the definitive reference for PDF/UA validation. Two notes/references violations require human testing (proper tag usage); two are machine testable (ID presence and uniqueness). For the most current information, consult the PDF Association and W3C WCAG guidelines.