For example a Button component has a default background property of: "image://theme/meegotouch-button"+__invertedString+"-background"+(position?"-"+position:"
or
A ToolIcon's platformIconId could have a value of "toolbar-view-menu" and automatically it is the equal sign like icon in the tool bar.
Thank you very much!
Here it is: http://www.developer.nokia.com/Community/Wiki/MeeGo_Harmattan_QML_ToolIcon_Element_and_Various_icons