EpubChapterMergeOptions

Explicit replacements for second-chapter body identifiers, excluding shared merge containers. Fragment URLs and document-local relationships are repaired. CSS selectors remain unchanged unless RewriteChapterSelectors is enabled. Fragment-only URLs in retained stylesheets naming changed IDs are rejected as ambiguous. At most 10,000 replacements.

Repair selectors in both source chapters, applying the identifier map only to the second chapter and retaining separate private copies of each chapter's linked stylesheets and imports. Requires AppendSecondStyles. Supports hash and id attribute selectors in ordinary/nested rules and media/supports/layer/container/scope groups. Declaration order and custom-property values are preserved. Partial id attribute comparisons use actual source and repaired values; destination-only hash identifiers stay nonmatching with their original specificity. Attribute comparisons on document-local relationships and resource-bearing attributes follow actual repaired values, using an explicit unprefixed type in the same compound selector when available, including rebased URLs and private stylesheet paths. Partial or multivalued matches can expand into at most 256 exact alternatives and 64 KiB of CSS, using :is when needed. Irreducible ambiguities and unsupported syntax fail atomically. Reader support for :is, :where and nested CSS remains independent.

Allow differing root/body language and direction by wrapping the second chapter's body content in a div with its effective language and direction. Other scaffold conflicts still reject the merge. Explicit auto direction on either source root/body is unsupported. Wrapper structure can affect CSS; this option does not isolate styles or establish equivalent reader layout.

Preserve each source body's frontmatter, bodymatter or backmatter partition on a section around its content before merging. Other body semantic tokens and attributes must remain compatible. The second chapter's boundary is placed inside its partition. Added sections can affect CSS selectors; this option does not isolate styles or establish equivalent reader layout.

Keep each body's id/xml:id, class, style, title, lang/xml:lang, dir and unnamespaced data-* attributes on a separate div around its content. Identifiers and local references remain independently addressable; collisions require SecondChapterIdMap. Other body attributes must still be compatible, and differing root language/direction requires PreserveSecondChapterLanguageAndDirection. Body-specific selectors, box layout and inherited styles can change; this option does not isolate CSS or establish equivalent reader layout.

Retarget EPUB 3 metadata meta/link refinements from the removed manifest item and spine position to the retained entries. Metadata nodes, IDs, values and refinements of those nodes remain intact. If the retained spine position has no ID, it takes the removed position's ID. The caller explicitly applies both chapters' assertions to the merged resource/position; values are not deduplicated or semantically reconciled. Structural references and extension refinement attributes remain errors.

Style reconciliation policy. Defaults to rejecting different chapter heads.