A YAML-based mechanism for working with table metadata. Supports compact syntax for creating, modifying, viewing, exporting, importing, displaying, and plotting metadata coded as column attributes. The 'yamlet' dialect is valid 'YAML' with defaults and conventions chosen to improve readability. See ?yamlet, ?decorate.data.frame and ?modify.default. See ?read_yamlet ?write_yamlet, ?io_csv, and ?ggplot.decorated.