Many file types can be identified by using what’s known as a file header. A file header is a ‘signature’ placed at the beginning of a file, so the operating system and other software know what to do with the following contents.

Many electronic discovery applications will use the file header as a means to verify file types. The common fear is if a custodian changes a files extension or the file wasn’t named using an applications default naming convention, that file will be missed during electronic discovery processing. For example, if I create a Microsoft Word document and name it ‘myfile.001’, instead of ‘myfile.doc’ and then attempt to locate all Microsoft Word files at a later date, I would miss the file if I were looking for all files ending in ‘.doc’. There are specific file extensions associated with the native application.