Yellow signs with a black triangle signs warn the persons of a particular hazard or hazardous condition that is not likely to be life threatening. The black triangle will incorporate a black symbol or exclamation mark. Background colour is to be yellow and text when used will also be black.
From the current AS 1319 standard for workplace safety signage the term warning now replaces the previous term of caution. The change now makes for more consistent messaging across roads signs and water safety signs (neither term is now actually used on signs). These WARNING signs are also defined as a subdivision of signs generalised under the term hazard. The other being DANGER signs.