Set EPUB Language Metadata to Match the Actual Publication

For a new EPUB, decide the publication's primary language when its source information is first created, not as a last-minute export fix. Enter ja for a Japanese publication or en for an English publication, then read dc:language back from the first exported EPUB. This article covers that initial decision for one new book.

The Stage 4 run started the Japanese and English samples in separate empty workspaces with no series information. Each was configured as a new publication. It did not preserve an existing Japanese edition and convert it into English.

Answer: Set the first language value from the new book's body

An initial setup has a short sequence: inspect the body and chapter labels, choose one primary publication language, enter that language in the source card, and read the same value back from the exported package. Naming a file “English edition” does not set the metadata inside it.

This publication-level choice is separate from language markup on a short quotation inside a multilingual book. It is also separate from changing an edition that already exists. The acceptance rule here is that the first language entered for a new publication matches dc:language in that publication's first artifact.

Initial-setup card: Start each book without prior series data

In the article-specific records, both language workspaces opened with zero tabs and no series information. Two chapters were then added to each, and each workspace received its own first publication setting.

The English sample is an independent control for the same initial decision, not an “after” state produced by changing the Japanese sample. That distinction keeps this workflow separate from an edition-conversion article.

Procedure: Enter, export, and read back the first value

Use this workflow for a new publication:

1. Read the selected body and chapter labels and choose the publication's primary language.
2. In a new workspace with no series information, enter title, author, publisher, output name, and language together.
3. Select the two source chapters and review the first export plan for chapter count and destination.
4. Export the EPUB for the first time.
5. Read dc:language from the exported OPF.
6. Check that the navigation labels match the selected body and chapter-label language.
7. Run local structural validation. If a value differs, correct the original source-card field or chapter label and export again.

The 20 Stage 4 commands are the combined total for performing this initial setup independently in Japanese and English. Preserving an old edition, duplicating it, or overwriting ja with en is not part of this procedure. STUDIO-418 owns that edition-change workflow.

Measured result: Both first-time settings read back correctly

The article-specific status was passed. The first Japanese setting produced ja in the OPF, Japanese navigation labels, and valid: true. The independent English setup produced en, English navigation labels, and valid: true.

The recorded values were ja_language: ja, en_language: en, separate_output_names: true, ja_nav_has_japanese: true, and en_nav_has_english: true; both local validations also returned true. The two samples show that the same initial-setting rule can be closed independently for ja and en.

A separate common regression sample used two chapters, horizontal writing, and version 1.6. Its nine-command export produced spine count 6, one image, no missing resources, nav and NCX documents, and valid: true. That checks the broader export path and is not the evidence for the initial language decision above.

Decide whether to close initial setup or move to another workflow

Initial language setup is complete only when the body and chapter-label language, source-card value, and OPF value form one consistent record for one new publication. An OPF mismatch returns to the source card. A navigation mismatch returns to the chapter labels.

If another language edition already exists or the original edition must be preserved while a new one is built, stop treating the task as initial setup. Move it to STUDIO-418's before-and-after edition workflow. This keeps “create a new book as en” distinct from “retain a ja edition and rebuild an English edition.”

Limits: Evidence covers local ja and en artifacts only

The result is limited to the measured ja and en samples. It does not establish support for other language codes, passage-level multilingual markup, translation quality, or edition conversion.

Retailer metadata fields, retailer review, and external-reader language presentation were not tested. valid: true is a local package result, not universal retailer acceptance or identical rendering in every reading system.

What Rune Studio covers

Rune Studio's documented EPUB wizard allows the manuscript language to be selected as Japanese or English alongside series information, chapter order, navigation, version, and publication date. Its public feature list also describes language-dependent navigation, colophon, and date formatting. Those are documented Stage 3 capabilities.

The first-time setup in empty workspaces, the ja and en OPF values, separate output names, language-matched navigation, and two successful local validations are Stage 4 observations. General package requirements are available in W3C EPUB 3.3, and the documented product scope is summarized on the Rune Studio website.

Conclusion: Close the first setting by reading it back from the first export

For a new book, choose the primary language from the body and chapter labels, enter ja or en when the publication information is first created, and read dc:language and navigation labels from the first artifact. Close initial setup only when those values agree.

The Stage 4 run performed that process independently in two workspaces that began without series information. Both OPF values, navigation languages, output names, and local validations matched. If the job instead requires preserving an existing edition and creating another language edition from it, use the separate change workflow in STUDIO-418.