Customization of the user interface is done by modifying the XML-based customization (CUIx) file with the Customize User Interface (CUI) Editor. 
You can edit customization (CUIx) files to make the following changes: 
- Add, delete, or change user interface elements, such as ribbon tabs and panels, and Quick Access toolbars 
- Create or change workspaces 
- Create or change macros and tooltips for commands 
- Create or change double-click actions 
- Create or change keyboard shortcuts and temporary overrides 
- Control the properties displayed when using rollover tooltips and the Quick Properties palette 
- Create and load new CUIx files 
 
Customizable User Interface Elements
The CUI Editor allows you to create and manage commands that are used to define the actions of a user interface element. After a command is defined, it can be used to create a button or a response to an action in the drawing area. You can customize 
- Quick Access toolbar 
- Ribbon tabs 
- Ribbon panels 
- Ribbon contextual tab states 
- Toolbars 
- Pull-down menus 
- Quick properties 
- Rollover tooltips 
- Shortcut menus 
- Keyboard shortcut and temporary override keys 
- Double click actions 
- Mouse buttons 
- Workspaces 
- Legacy user interface elements (tablets, tablet buttons, and image tile menus)