In this paper, we present a methodology for the construction and use of corporate knowledge repositories. We consider here only the "textual component" of corporate knowledge -- i.e., all sort of economically valuable, natural language (NL) documents like news stories, telex reports, internal documentation, normative texts, intelligence messages, etc. In this case, we suggest that the construction of effectively usable corporate knowledge repositories can be achieved with the translation of the original documents into some type of conceptual format. The "metadocuments" obtained in this way can then be stored into a knowledge repository (knowledge base) and, given their role of advanced document models, all the traditional functions of information retrieval, (searching, retrieving and producing an answer) can be directly executed on them. We illustrate here the architecture of a prototypical, implemented system used to exploit a knowledge repository of metadocuments.