GPO's Federal Digital System (FDsys) automates the collection and dissemination of electronic information from all three branches of the United States federal government. Information is submitted directly into FDsys, permanently available in electronic format, authenticated and versioned, and publicly accessible for searching and downloading. FDsys relies on three key system components to accomplish this: 1) A content management system that securely manages digital content to safeguard content integrity and authenticity, 2) A preservation repository that follows archival system standards to ensure long-term preservation and access to digital content, and 3) An advanced search engine combines extensive metadata with modern search technology, allowing the public to find federal government publications.FDsys is a metadata driven system. It has been developed to utilize multiple metadata creation techniques, including parsing from unstructured or semi-structured text, transformations from structured formats, transformations to apply constants, and manual metadata entry. Using these techniques, GPO is able to create and store metadata to power the search engine on the FDsys.gov web site. This metadata is used to deliver advanced search, field operator search, search result filters (aka faceted navigation), and hierarchical browsing of documents. It is also used to provide downloads of descriptive metadata files in MODS XML. This emphasis on source metadata makes FDsys a dynamic, rich, flexible, powerful, and transparent system for document search and access. This paper will discuss different methods used to create metadata, how FDsys descriptive metadata is stored, and how this metadata is utilized by the FDsys search engine.