In addition to extracting all compressed and container files, DISCO extracts any files embedded within other files. DISCO will then create separate, but related, records for both the original file along with the embedded file(s).
For example, Let's say you have an Excel document embedded within another Office document, such as a PowerPoint. DISCO will create one document (or record) for both the Powerpoint and the Excel. Furthermore, the Excel file will appear as an attachment to the PowerPoint.