System warning icons also belong to the broader area of ISO standard warning signs. These warning icons, first designed to regulate automobile traffic in the early 1900s, have become standardized and widely understood by users without necessity of further verbal explanations. In designing software operating systems, different companies have incorporated and defined these standard symbols as part of their graphical user interface. For example, the Microsoft MSDN defines the standard icon use of error, warning, information and question mark icons as part of their software development guidelines.
Different organizations are actively involved in standardizing these icons, as well as providing guidelines for their creation and use. The International Electrotechnical Commission (IEC) has defined "Graphical symbols for use on equipment", published as IEC 417, a document which displays IEC standardized icons. Another organization invested in the promotion of effective icon usage is the ICT (information and communications technologies), which has published guidelines for the creation and use of icons. Many of these