# EPUBCheck OPF-066: pagination source missing, how to fix it

Source: https://epubcc.com/epubcheck/opf-066/ (updated 2026-11-04)

EPUBCheck OPF-066 is an error message: “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.” The content marks print page breaks but the metadata does not say which print edition the page numbers come from. EPUB requires the pagination source when page-break markers are present.

- Official message (EPUBCheck 5.4.0): 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.
- Default severity: Error

## Typical causes

- Page-break markers or a page list added without identifying the source edition.
- The dc:source element removed while page breaks stayed in the content.
- A dc:source present but not refined with source-of.

## How to fix it

1. Find the identifier of the print edition (usually its ISBN).
2. Add it as dc:source and refine it with source-of, for example <dc:source id="src">urn:isbn:…</dc:source> and <meta refines="#src" property="source-of">pagination</meta>.
3. If the page numbers do not come from a print edition, remove the page-break markers.

## When it's not this

If the page breaks are fine but there is no page list, that is NAV-003.

## Sources

- EPUB 3.3, §D.3.11 source-of: https://www.w3.org/TR/epub-33/#sec-source-of (read 2026-11-04)
- EPUB Accessibility 1.1, §3.4.1.3.1 Pagination source: https://www.w3.org/TR/epub-a11y-11/#sec-page-src (read 2026-11-04)

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EpubCC.