Back to Error DirectoryW3C EPUBCheck Standard
OPF-066Critical Ingestion Error

Missing "dc:source" or "source-of" pagination metadata. The paginat...

Missing "dc:source" or "source-of" pagination metadata. The pagination source must be identified using the "dc:source" and "source-of" properties when the content includes page break markers.

Automated 1-Click Fix Ready

Fix all OPF-066 errors in your EPUB automatically

PreFlight checks for OPF-066 issues in memory and provides 1-click remediation during client-side packaging.

Scan & Fix Now

What This Error Means in Plain English

EPUBCheck detected Missing "dc:source" or "source-of" pagination metadata. The pagination source must be identified using the "dc:source" and "source-of" properties when the content includes page break markers.. Digital reading systems and bookstores require standard conformance to ensure compatibility across all reading apps.

Why Retailers & EAA Regulations Block This File

Automated book distributors (Apple Books, Amazon KDP, Kobo, and IngramSpark) run strict EPUBCheck validation on ingest and reject non-compliant files.

Technical Specification: W3C EPUBCheck rule OPF-066: Missing "dc:source" or "source-of" pagination metadata. The pagination source must be identified using the "dc:source" and "source-of" properties when the content includes page break markers.

Manual Fix Instructions (for Sigil / Calibre)

  1. Locate the file and line flagged under rule OPF-066 in your EPUB editor (Sigil or Calibre).
  2. Apply the required syntax correction matching the OPF-066 specification.
  3. Re-pack and validate with PreFlight EPUB to confirm zero residual errors.