By default, DiskSorter classifies and categorizes files using the 'Default File Classification Plug-in', which is capable of recognizing more than 3,000 of the standard file types and formats and allows one to organize them into a logical file hierarchy. In addition, a number of advanced file classification plug-ins are available for registered users of DiskSorter Ultimate and DiskSorter Server.

Finally, DiskSorter Ultimate provides the ability to add user-custom file classification plugins and customize the built-in file classification plug-ins allowing one to classify and categorize files according to the user-specific needs and requirements. In order to add a custom file classification plug-in, select the menu 'Tools - Manage Plugins', press the 'Add' button, specify a unique file classification plug-in name and then use the file classification plug-in designer dialog to create your custom file categories and file classes.

Another option is to customize a built-in file classification plug-in by adding support for one or more additional file type or file categories. In order to customize a built-in file classification plug-in, select the menu 'Tools - Manage Plugins', select the required file classification plug-in item, click the right mouse button and select the 'Copy Plug-in' menu, specify a new plug-in name and then double click on the newly copied plug-in item to open the plug-in copy in the file classification plug-ins designer dialog.