Created in a semantic scheme known as the Anglo-American Cataloging Rules, and stored in a framework called the MARC format, these records described the world's documented knowledge. These external metadata records, or surrogates, referenced resources that existed separately from the resources they described. This traditional form of metadata deployment often allows the creator of the surrogate the ability to customize the agent parsing the metadata. A common case is the cataloger who not only creates the bibliographic record, but can also adjust the way the library's OPAC renders it. RDF and XML offer a potential means to enhanced resource discovery on the Web.
Embedded metadata is a more recent event.
At the same time, content providers discovered a means to increase access to their works. By embedding terms within metatags in their HTML documents, Web developers enhanced the chan- ces of being indexed and having higher ranking by search engines. However, much of the early metadata implementations were of a dubious nature. Spamming, the overloading and repeating of terms within metatags, caused many search engine companies to change the way their systems treated metadata. These include AltaVista, Go, HotBot, and Inktomi.