PDF scanner rules

Explore detailed insights into the PDF scanner rules designed for accessibility checks.

PDF Scanner uses an open-source PDF rule engine, to validate PDF documents against established accessibility standards.

The following standards covered are used to validate PDF documents for accessibility:

• ISO 14289-1 (PDF/UA-1)
• ISO 14289-2 (PDF/UA-2)
• WCAG 2.2 (A and AA levels)

PDF/UA-1 coverage

You can find the updated list of rules validated under ISO 14289-1 (PDF/UA-1) on this open source profile.

The following are the key areas covered under ISO 14289-1 (PDF/UA-1):

• Conformance Requirements (6.x) – file structure, metadata, embedded files

• Content Rules

  • 7.1 General structure and tagging

  • 7.2 Text content tagging

  • 7.3 Graphics and drawing objects

  • 7.4 Headings (numbered / unnumbered)

  • 7.5 Tables

  • 7.6 Mathematical expressions

  • 7.9 Notes and references

  • 7.10 Optional content

  • 7.11 Embedded files

  • 7.15 XFA content

  • 7.16 Security restrictions

  • 7.18 Annotations

    • Types, tab order, forms, links, media, PrinterMark

  • 7.20 XObjects

  • 7.21 Fonts (composite fonts, embedding, metrics, encodings, .notdef glyph)

PDF/UA-2 coverage

You can find the updated list of rules validated under ISO 14289-2 (PDF/UA-2) on this open source profile.

The following are the key areas covered under ISO 14289-2 (PDF/UA-2):

• Logical Structure and Tagging

  • 8.2 Structure types and hierarchy

  • 8.4 Text representation and natural language declaration

  • 8.6 Text string objects

  • 8.7 Optional content groups

  • 8.8 Intra-document destinations

  • 8.9 Annotations (semantics, tab order, alt descriptions)

  • 8.10 Forms – field structure, context, and metadata

  • 8.11 Metadata – general and interactive aspects

  • 8.14 Embedded files – inclusion and usage validation

WCAG 2.2 coverage

You can find the updated list of rules validated under WCAG 2.2 success criteria (at A and AA levels) on this open source profile.

The checks align with WCAG 2.2 success criteria at A and AA levels as follows:

• Perceivable

  • 1.3 Adaptable (Info and Relationships, Orientation)

  • 1.4 Distinguishable (Reflow, Contrast Minimum, Resize Text, Visual Presentation)

• Operable – 2.4.9 Link Purpose (Link Only)

• Robust – 4.1.2 Name, Role, Value