Provides for signs using a system of coded shapes and colours with symbols which pictorially describe hazards (i.e. signs for conveying safety instructions without relying on any 'text' message) and signs with text (words and numerals) messages (including recommendations for multi-lingual signs); accident prevention tags are also covered. The signs are classified as 'regulatory', 'caution' (warning), 'emergency-related information' (including fire signs). All standard symbolic (pictorial) signs are reproduced in colour and examples are included, also in colour, of text-type signs. Photometric and colorimetric properties of the sign materials are dealt with, and recommendations on styles and sizes of sign lettering are included.