Identify the source of pagination so users can be sure the digital publication will be useful for their needs.



Example 1 — Page break source identification (pageBreakSource)

Unlike having to pair dc:source and source-of properties to identify the pagination source, the pageBreakSource property only requires the identifier for static page source (i.e., it can do in one property what previously required two).

<meta property="pageBreakSource">urn:isbn:9781234567891</meta>
Example 2 — Page break source identification (source-of)

This example uses the old source-of property to identify the pagination source. This method is no longer recommended. Refer to the FAQ entry below for more information.

<dc:source id="pg-src">urn:isbn:9781234567891</dc:source>
<meta property="source-of" refines="#pg-src">pagination</meta>

Frequently Asked Questions

Should I use the source-of or pageBreakSource property?

The older way to identify the pagination source in EPUB is through a combination of dc:source and source-of metadata properties. This approach has two serious flaws, however: one is that it only works for EPUB (refining metadata does not work in other frameworks); the other is that it does not work for digital-only editions (i.e., where the page breaks do not have a source).

The replacement method that uses only a single property called pageBreakSource is now preferred (see example 7). Although it will take another revision of EPUB before this property is fully integrated into the standard, there are no barriers to using it. Epubcheck correctly validates the property.

The value of the pageBreakSource property can be set to "none" if the page breaks were created specifically for the digital edition, overcoming the problem of using dc:source.

Refer to Page Source Identification for more information about the pageBreakSource property.

What if the pagination source does not have a unique identifier like an ISBN?

It is not required that the pageBreakSource property contain a unique identifier, only that it uniquely identify the source. In the absence of a unique identifier, create a unique name for the source document using the information you have about it.

There are many types of documents with static pagination but without unique identifiers that can be represented as EPUBs — PDF manuals, word processing documents, etc.

For these types of documents, you can minimally use the title to identify the page break source. For greater specificity, add the author(s), creation date, etc. to the identifier.

<metadata …>
<meta property="pageBreakSource">
ACME Explosive Tennis Balls - 
User Manual, 5th Edition, PDF


Although the page list and page break markers are the technologies that allow users to access static page break locations, without knowing the source of the pagination, users cannot determine the usefulness of a digital publication. A student in a classroom, for example, needs to know whether the pagination was derived from the same version of a print book that the rest of their class is using.

The source of the pagination is identified using the pageBreakSource property.

<meta property="pageBreakSource">urn:isbn:9780123456789</meta>

The value of the property is a unique identifier for the statically paginated source, such as its ISBN.

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