EpubCCWhat is Dublin Core metadata (dc:*)?
Updated:
EPUB metadata uses Dublin Core elements in the package document: dc:identifier, dc:title and dc:language are required, and dc:creator, dc:date, dc:publisher and others are optional. EPUB 3 also requires a dcterms:modified timestamp.
Why it matters when you convert a PDF to EPUB
A PDF often has a useless internal title (a file name like "Microsoft Word - draft3.docx") or none. A converter has to choose a real title, detect the language of the text for dc:language (which drives hyphenation and text-to-speech) and generate a stable unique identifier.
How EpubCC handles it: dc:title is the PDF's metadata title when it is not junk, otherwise a heading from the first three pages, then the largest heading in the book, and only then "Untitled", never a machine-made file name. dc:language is detected from the script and common words of the text, dc:creator comes from the PDF metadata when it has one, and dc:identifier is a UUID derived from the content.
Related terms
EPUBCheck messages about this
OPF-030The unique-identifier "…" was not found.OPF-053Date value "…" does not follow recommended syntax as per http://www.w3.org/TR/NOTE-datetime:….OPF-072Metadata element "…" is empty.OPF-085"dc:identifier" value "…" is marked as a UUID, but is an invalid UUID.OPF-092Language tag "…" is not well-formed: …OPF-007Re-declaration of reserved prefix "…".OPF-048Package tag is missing its required unique-identifier attribute and value.OPF-054Date value "…" is not valid as per http://www.w3.org/TR/NOTE-datetime:….OPF-055… tag is empty.OPF-065Invalid metadata declaration, probably due to a cycle in "refines" metadata.
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