What counts as metadata

  • Title, subtitle and series name and number.
  • Contributors (author, illustrator, translator, editor) with consistent spellings.
  • ISBN, format, trim size, page count, publication date, price per territory.
  • Description, author biography and review quotes.
  • Subject categories, keywords, audience and age range.

The book trade exchanges this information in a standard format called ONIX; self-publishing platforms collect the same fields through their upload forms.

Subject categories

Booksellers classify books with subject schemes: BISAC in North America and Thema internationally. Stores map these codes to their own browse categories. Choose the most specific accurate categories, not the most popular ones — a precise category puts you in front of readers who want exactly your kind of book, and makes bestseller lists in that niche achievable. Retailers such as KDP let you choose a limited number of categories (currently up to three), so pick deliberately.

Keywords

Keywords help search engines inside stores match your book to queries. KDP, for example, provides seven keyword fields.

  • Think in reader phrases: "cozy mystery with a bookshop", "grief journal for widows", "space opera found family".
  • Include setting, time period, character types, tropes, tone and use cases.
  • Do not repeat words already in your title or categories.
  • Never use other authors' names, trademarks or misleading terms — retailers prohibit it.

Series and contributor data

Link series books with the same series name and correct numbers so stores group them and readers find book two. Keep author names identical across formats — "J. A. Smith" and "Jane Smith" may be treated as different people.

Audience

For children's and young adult books, set age and grade ranges accurately. They affect which shelves, lists and library systems your book appears in.

Review and refresh

Metadata is not set-and-forget. Revisit categories and keywords when you learn more about who is buying the book, when you release a sequel, or when a season or anniversary makes your subject newly relevant.