1. A computer system comprised of at least one computer and at least one data storage device for determining the relative geneology of a predetermined set of versions of a document data files stored on the system, said system comprising: an extraction module adapted by logic to extract a set of at least one RSID values from each of the predetermined set of document versions, construct generate and store in computer memory a data structure that encodes the geneology of the predetermined set of document versions; a logic module adapted by logic to select at least one pair of RSID sets comprised of a first RSID set and a second RSID set corresponding to at least one selected pair of versions of the document associated with the corresponding at least one pair of selected RSID sets, and apply at least one of a predetermined set of logic rules to the selected pair of RSID sets said logic rules being at least one of: (i) testing whether the pair of RSID sets are identical; (ii) testing whether any of the RSID values in the first set are the same as any RSID values in the second set; (iii) testing whether all of the RSID values in the first set are a proper subset of the RSID values of the second set; or (iv) testing whether neither the first set of RSID values is a subset of the second set of RSID values nor the second set of RSID values are subset of the first set of RSID values, and to update the stored data structure with an identifier entry for one of the versions in the corresponding at least one pair of versions referring to its genealogical relation to the other version.