# What is Dublin Core metadata (dc:*)?

Source: https://epublab.com/glossary/dublin-core-metadata/ (updated 2026-11-03)

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.