The selection of combination signage is designed to cover many of the other regulations and requirements of all types of signs. It is primarily focused on areas that involve a number of different regulations on one sign rather than having a number of different signs.
Many spaces have recognised hazards and these multi-purpose signs are designed to adequately inform without the need for multiple signs.
They convey a combination of more than one instruction i.e. a hazard and prohibition message or multiple messages requiring different symbols.