What does “COF” mean?

CoF mean

Coefficient of Friction (“COF) is the relative slip resistance of tile. The COF test disclosed by Daltile is a laboratory or field test established by the American Society for Testing and Materials (ASTM) to provide its customers comparable slip resistance values for each of its floor tiles. The measurements disclosed are designed to be one important factor to consider in evaluating slip resistance. Other factors can affect slip resistance, such as the degree of wear on the shoe and flooring material; presence of foreign material, such as water, oil and dirt; the length of the human stride at the time of slip; type of floor finish; and the physical and mental condition of humans.