Posted on by & filed under ebooks, epub.

The ePub format allows for a fairly comprehensive set of book-friendly metadata, mostly drawn from the Dublin Core set of terms. Knowing what metadata to use and how it will appear in today’s and tomorrow’s readers is key; here are some recommendations:


Two elements describe authorship of a work: dc:creator and dc:contributor. As you might guess, dc:creator designates the primary authorship, though there can be more than one.

Each author should be in their own element.. Don’t do this:

<dc:creator>James F. Smith, Thomas Jones</dc:creator>

Instead use:

<dc:creator>James F. Smith</dc:creator>
<dc:creator>Thomas Jones</dc:creator>

We recommend that anyone who had any kind of significant authorship role be marked as a dc:creator. Most reading systems use this element to discover or search for the author name, so ensure that individual authors in a multi-author work are so tagged.

A contributor designation is appropriate to describe individuals who had a non-primary role in the work. For example, if a multi-author work had multiple editors, or you want to capture additional staff like proofreaders, illustrators or the like, then use dc:contributor.

<dc:contributor>Alice Proofreader</dc:contributor>

File maker

ePub allows ebook creators to indicate how the values in these elements should be sorted. Name sorting, especially internationally, is a surprisingly difficult problem.

We recommend listing the author names in display order (usually First Middle Last) in the element text, and then setting opf:file-as to Last, First Middle, or whatever is appropriate in your source language.

<dc:creator opf:file-as="Smith, James F.">James F. Smith</dc:creator>
<dc:creator opf:file-as="Jones, Thomas">Thomas Jones</dc:creator>

Role playing

ePub extends Dublin Core by providing the opf:role attribute. This allows ebook creators to more precisely describe the contributions made by individuals listed in dc:creator and dc:contributor. It’s always a good idea to fill this out, even if not all reading systems display it:

<dc:creator opf:role="edt" opf:file-as="Smith, James F.">James F. Smith </dc:creator>
<dc:creator opf:role="edt" opf:file-as="Jones, Thomas">Thomas Jones</dc:creator>
<dc:creator opf:role="aut" opf:file-as="MacNeil, Lisa">Lisa MacNeil</dc:creator>

The recommended list of values for opf:role come from the MARC code list.


10 Responses to “Practical ePub metadata: Authorship”

  1. Dave Cramer

    Unfortunately, ADE will only display the contents of the first dc:creator element above the NCX display. So some customers have required us to put all authors in a single dc:creator, wrong as that is.

  2. Liza Daly

    That’s unfortunate but I don’t believe that publishers who are making significant investments in digitization projects should be working around bugs in ADE that are trivial to fix.

  3. bowerbird

    the other guy’s bugs are always trivial.

    except, of course, when they’re not…


  4. Xelle

    In our digital publishing process, we also choose to put all the main authors in one element, to comply with ADE… All our publishers currently want to have DRM, so ADE is not one reader among the others, it’s the only reader we have to work with.
    They don’t understand yet all the consequences of this choice on their ebooks’ quality…

  5. Mike Cook

    How would you handle something such as Andrew Lang’s Fairy Books in the NCX file?

    Andrew Lang

    As many reading systems will assign the first dc:creator it encounters as the author. Because I always place “aut” first this will be shown as “Various” (this is how Adobe DE works), though it would probably be more useful to have the author shown as “Andrew Lang”.

    In these situations would you recommend I put the “edt” first, or stay with my current hierarchy (below) and live with the fact that the author will be shown as “Various”?

    dc:creator opf:role=”aut”
    dc:creator opf:role=”edt”
    dc:creator opf:role=”ill”

  6. Liza Daly

    Personally I hate working around bugs in readers when composing an ebook. The ebook file will long outlast the bugs, and should be written with that in mind.

  7. Nic Gibson

    I’m terribly late to comment here but I was the person who required Dave Cramer to abuse the mechanism. I totally agree that we should never have to work around bugs in the reader but the editorial staff at the major trade publisher I worked for at that time were absolutely opposed to any ebook being released that didn’t show all authors on the author line. We raised this with Adobe who accepted that is was a bug but that didn’t resolve the commercial issue.

    I’m currently writing an ePub conversion spec for another major trade publisher (they currently require simply that their conversion partners work to the IDPF specs and the output is too variable with that wide a specification). I’ve found myself in exactly the same situation. As a result I may have to create the same requirement again.

  8. elmimmo

    How about one creator with several roles? Say, author and illustrator are the same person, but then there are also other creators with their own role.

  9. Liza Daly

    They would just be expressed by multiple elements:

    <dc:creator opf:role=”aut”>person</dc:creator>

    <dc:creator opf:role=”edt”>person</dc:creator>