Flat rate is common in broadband access to the Internet in the USA and many other countries. A charge tariff is a class of linear rate, different from the flat rate, where the user is charged by the uploads and downloads (data transfers).
MUI stands for Multilingual User Interface and .dll.mui files are simply libraries(Dlls) that contain resources dedicated to localization : for an application to support multiple languages,dlls containing specific resources must be available eg language resources(arabic,french,english,chinese....
Using DLL Files. 1  1. Understand what a DLL file is. A DLL (dynamic link library) is a Windows file that is used by program to call upon existing functions. 2  2. Know that the average user doesn't need to open or interact with DLL files. For most users, DLL files will exist in the background. 3  3. Register a new DLL.