archives, museums, libraries, and manuscript repositories to list and describe their holdings in a manner that would be machine-readable and therefore easy to search, maintain and exchange. Since its inception, many archives and special collections have adopted it. In addition to the development and maintenance work done by the Society of American Archivists and the Library of Congress, the Research Libraries Group (RLG) has developed and published a set of "Best Practice" implementation guidelines for EAD, which lays out mandatory, recommended, and optional elements and attributes. RLG has also provided a kind of clearinghouse for finding aids in EAD format, known as ArchiveGrid. Member libraries provide RLG the URL for their finding aids; RLG automatically harvests data from the finding aids, indexes it, and provides a search interface for the index, thus giving researchers the ability to search across several hundred institutions' collections with a single query. RLG also has developed the "RLG Report Card," an automated quality-checking program that will analyze an EAD instance and report any areas where it diverges from the best practices guidelines. SAA's Technical Subcommittee for Encoded Archival Description, which include international representation, embarked on a revision of the EAD standard in 2010. The latest version, EAD3, was released in August 2015. Adoption A number of repositories in the United States, Canada, the United Kingdom, France, Australia and elsewhere have adopted and implemented EAD with varying levels of technical sophistication. One of the most ambitious efforts is the Online Archive of California, a union catalog of over 5,000 EAD finding aids covering manuscripts and images from institutions across the state. The French National Library Francois Mitterrand publishes more than 90,000 EAD finding aids covering archives and manuscripts. EAD element set The EAD standard's XML schema specifies the elements to be used to describe a manuscript collection as well as the arrangement of those elements (for example, which elements are required, or which are permitted inside which other elements). The EAD tag set has 146 elements and is used both to describe a collection as a whole, and also to encode a detailed multi-level inventory of the collection. Many EAD elements have been, or can be, mapped to content standards (such as DACS and ISAD(G)) and other structural standards (such as MARC or Dublin Core), increasing the flexibility and interoperability of the data. EAD 1.0 was an SGML document type definition (DTD). EAD 2002, the second