Publication identifier

[dauwhe]

Mailing list thread:

https://groups.google.com/forum/#!searchin/epub-working-group/container%5D$20publication$20identifier/epub-working-group/-mHgOTK0Kik/J3T2jL6yBQAJ

[dauwhe]

Makoto (copied from the original thread) writes:

Somebody asked me if an BFF-version of a publication needs a identifier different from the ZIP-and-XML version of the same publication. I suppose that the answer is yes.

But I am even wondering what does a publication identifier means. Since we allow exploded publications, some files in a publication and others in the same publication might be maintained at different web sites by different organizations. For example, some content documents may be shared by many publications, and may be changed occasionally.

In this scenario, are publication identifiers useful? The author of a manifestation might not be aware of all changes to content documents, and thus cannot update identifiers.

Regards, Makoto

[dauwhe]

Hadrien (copied from the original thread) writes:

Hello Makoto,

Two very interesting questions indeed.

For the identifier, I don't see any reason why we should be using something different, at least for the part expressed by dc:identifier.

That said you're absolutely right that the second part of the identifier (dc:modified) is going to be tricky with BFF. There are two main reasons for that:

• as you've mentioned, the publication could be made of resources that are not controlled by the author of the manifest
• even if the author controls every content document, it's likely that they will be updated while the dc:modified value of the manifest remains the same

BFF publications are much more "alive" than our current EPUB, and cache headers per resource will provide a more complete outlook of things than the dc:modified attribute.

I still think that the publication identifier is useful though, but how we assign and use such identifiers might evolve over time.

Hadrien

[murata2makoto]

The first half of my original question is rather different. Consider a BFF converted from an EPUB 3.0.1 publication. Does the BFF and the original have the same identifier?