A computer-based system and method of retrieving information pertaining to Web documents on a computer network is disclosed. The method includes maintaining an address map that associates primary addresses with secondary addresses. A primary address includes a network retrieval protocol and a network address. The secondary address may include a different retrieval protocol or a different network address from the primary document address. A Web crawler retrieves a Web document using the primary document address, and determines whether the address map contains a secondary document address prefix corresponding to the primary document address prefix. If a secondary document address prefix exists, the Web crawler creates a secondary address, retrieves additional information pertaining to the Web document, and combines the additional information with the data retrieved from the Web document. The combined data may be stored in an index, and subsequently used to perform a document search.