Use of Icons Provided by Firefox

During the development of the ExpressionWidgets I feel I needed to use icons - like warnings, question marks or other built in meaninful iconsets. This action came out possibly inspired by the original samples and also motivated myself to think about an extended API function that could provided this effect to a further degree. After some research using the Mozilla source code view tool ( ) additional icons where found:

These icons were found when visiting the default theme directory which can be visualized using MXR.