There are literally hundreds of metadata schemas that publishers can use for their electronic documents or digital media. These schemas or structures of metadata are used for variety of purposes. There are metadata schemas designed solely for search optimization procedures. The Meta tags and the structuring of the text are created to conform to the algorithms used by search companies. There are also schemas specifically designed for digital creations such as photos, audio, and features.
Normally, the schemas used for metadata have their own standards. This is to allow the intended reader of the metadata to easily find or discover the information presented on the document or media.
For business and corporate information transactions however, stricter standards have been implemented for the metadata schemas. In fact, the ISO has standardized the metadata registry of companies. The standards specify the information that will be included in the metadata. Structures, languages, and specific elements of the metadata have been standardized also by the ISO.
Standardization of metadata schemas will facilitate communication between different enterprise applications or computer program. Through metadata, information exchange will be easier and faster.
Metadata schemas must also use a recognizable encoding system so that it can be utilized by a third party user. For example, a metadata schema encoded for markup language can be embedded on website pages. The metadata will not be readable on the interface unless users look into the source code of the web page. The metadata then can be visible to the user from the source code view.