sync(8) on macOS
The text ccb53d1bbe40, as macOS 26.5, macOS 26.4, macOS 26.3, macOS 26.2, macOS 26.1, macOS 26.0, macOS 15.6, macOS 15.5, macOS 15.4, macOS 15.3, macOS 15.2, macOS 15.1, macOS 15.0, macOS 14.6, macOS 14.5, macOS 14.4, macOS 14.3, macOS 14.2, macOS 14.1, macOS 14.0, macOS 13.5, macOS 13.4, macOS 13.3, macOS 13.2, macOS 13.1, macOS 13.0 shipped it. The page shows this text now.
force completion of pending disk writes (flush cache)