File types that are allowed to be uploaded to wiki can be specified in the following way. Go to “Admin” section, then at the end of the page click on “Configuration file manager.” In the dropdown menu, select “MIME configuration”. You will see a page with some brief info and links to more detailed instructions; under this text, find “User defined values section”. There, you can add/remove allowed file types. There are two entry fields: the left one indicates file extension, the right one - MIME type (which is of the form “general type/specific type”, e.g. “text/plain”). If MIME type is preceded by an exclamation mark, wherever a user clicks on a link with a file of such type, the file will be downloaded to the user's machine; otherwise, the file will be attempted to be opened in the browser's window.