.MainMenu_MenuBreak
Styles the break section between the menu items.
Within the main menu, I can not find an area that uses a menu break. Check the Module Settings menu for an example of the menu break class in action:
ModuleTitle_MenuBreak
.MainMenu_MenuBreak
{
border-bottom: #EEEEEE 1px solid;
border-left: #EEEEEE 0px solid;
border-top: #EEEEEE 1px solid;
border-right: #EEEEEE 0px solid;
background-color: #EEEEEE;
height: 1px;
}