MADS is the Metadata Authority Description Schema.
It is an XML schema for an authority element set that may be used to provide metadata about agents (people, organizations), events, and terms (topics, geographics, genres, etc.).
MADS serves as a companion to the Metadata Object Description Schema (MODS) to provide metadata about the authoritative entities used in MODS descriptions.
Currently we maintain a local MADS database and files for agents, and expect to include terms soon.