Today, the Internet can be seen as a global marketplace populated by a huge number of providers and consumers that exchange data from a wide range of domains. A combination of data from different sources for further automatic processing is often hindered by differences in the underlying modeling assumptions and representation. In addition, the available sources are in most cases semistructured, i.e., provide no fixed and explicitly specified schema. Therefore, an integrated use of Web-based data requires explicit information about its organization and meaning. In this paper we present a representation model wellsuited for explicit description of implicitly described semistructured data, and show how this model can be used for the integration of heterogeneous data sources from the Web.