A roundel in heraldry is any circular shape; in military use it is an emblem of nationality employed on military aircraft and air force flags, generally round and consisting of concentric rings of different colours. However, some corporations and other organisations also make use of roundels in their branding, employing them as a trademark, or logo, such as the famous roundels of BMW, ICI, and the London Underground.*******************In heraldry, a roundel is a circular charge. Roundels are among the oldest charges used in coats of arms, dating from at least the twelfth century. Roundels in British heraldry have different names depending on their tincture (colour). Thus, while a roundel may be blazoned by its tincture, e.g., a roundel vert (literally "a roundel green"), it is more often described by a single word, in this case pomme (literally "apple", from the French).*****************In French, blazon a roundel of either metal (or or argent) is a besant, and a roundel of any colour (dark tincture) is a torteau, with the tincture specified. One special example of a named roundel is the fountain. This is depicted as a roundel barry wavy argent and azure. That is, it is not filled in a single tincture, but with alternating horizontal wavy bands of blue and silver (or white). Because the fountain consists equally of parts in a light and a dark tincture, its use is not limited by the rule of tincture as are the other roundels. In their earliest uses, roundels were often strewn (semy) upon the field of a coat of arms, a design with as many names as there are tinctures. For example, a field semy of roundels argent could be called platy; a field semy of roundels sable could be called pellety. The precise number and placement of the roundels in such cases were usually left to the discretion of the artist. Because of their long use and simple outline, roundels are accorded status as a subordinary charge by most heraldic writers. The term roundel also describes a circular shield used for heraldic display (as opposed to other forms such as the more common escutcheon or lozenge). An example of arms borne on a roundel is the Coat of Arms of Nunavut.