New Category (Pre-defined commands)
The items in this category are not actually commands; instead they provide a 
way to add new (empty) elements to your toolbars via drag and drop.
  - New Button: Creates a new button with no function 
  defined. Use this if you want to create a button from scratch instead of 
  starting with a pre-defined command. 
  
 - New Menu: Creates a new drop-down menu. A menu has a label and 
  image but no function of its own; instead, it contains buttons and sub-menus. 
  
 - New Menu Button: Creates a new menu button, which is a combination of a 
  button (with a function) and a menu (a drop-down). 
  
 - Spacer: Creates a spacer, which is used to add padding or 
  right-justification to toolbars.