Explanation: PDF/A & metadata

ModernDoc targets long-lived, shareable PDFs.

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PDF/A basics

PDF/A is a family of ISO standards for archival PDFs. Key requirements:

• embed fonts
• avoid external dependencies
• include metadata
• constrain features that break future rendering

ModernDoc aims for PDF/A-4 where possible.

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Document metadata in LaTeX

Use \DocumentMetadata{...} at the top:

\DocumentMetadata{
  pdfversion=2.0,
  pdfstandard=a-4,
  lang=en-US
}

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Practical tips for PDF/A-friendly output

• Prefer vector images (PDF/SVG→PDF) for diagrams
• Keep raster images in RGB
• Avoid transparency-heavy assets if validation matters
• Keep fonts consistent and embeddable

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Validating output (optional)

Use a validator such as veraPDF to check archival compliance. If validation fails, it’s usually due to:

• missing font embedding
• image color profiles / transparency
• metadata issues