The National Marker Company sign with the legend âCAUTION - FIRE REGULATIONS DEMAND THAT THIS SPACE BE KEPT CLEAR AT ALL TIMESâ clearly informs the visitors or employees that the indicated space always needs to be kept clear as per the fire regulations. The caution sign helps enforce safety standards in a facility. The use of yellow text on a black base with black text on a yellow base in clear, bold letters ensures high visibility and easy readability of the message. The OSHA compliant caution signage has an NMC Sign Muscle coating to protect the text against fading, scratches, scuffing, mold, and moisture and complies with OSHA standard.