[1] dev:web_api:v3:write_requests [Zotero Documentation] (2016-03-31 01:11:19 +09:00 版) <https://www.zotero.org/support/dev/web_api/v3/write_requests>
As an alternative to individual version properties, the last-known library version can be passed via the If-Unmodified-Since-Version HTTP Header.