The work's title, by language. Keys are language tags ("ja", "en", …) plus "origin" for the title as the source itself writes it.

A map rather than one string because the same work legitimately has several titles, and a reader of Japanese wants a different one from a reader of English. Naming the languages in the contract (title_jpn and friends) would mean changing it again for the next source, so the source decides which keys it can fill.

A bare string is still accepted and read as { origin: "..." }.