The definition provided by Greenberg (2003) clearly describes the notion of metadata adopted by MTSR'05: "structured data about an object that supports functions associated with the designated object. [...] structured data, implies a systematic ordering of data according to a metadata schema specification [...], the object, is any entity, form of mode for which contextual data can be recorded [...]. The last component of the metadata definition given above refers to the functions associated with the designated object. The emphasis here is on the ability of metadata to support the activities and behaviors of an object."
Greenberg, J. (2003). Metadata and the World-Wide-Web. Encyclopedia of Library and Information Science, 1876-1888.