The term is almost always used to specifically refer to the parallels and meridians of latitude and longitude respectively in the geographic coordinate system. Grid lines for other coordinate reference systems, such as Universal Transverse Mercator, are commonly placed on maps for the same purposes, with similar meaning, and using similar design, but they are rarely called graticules. Some cartographers have used the term graticule to refer not only to the visual lines, but to the system of latitude and longitude reference itself;[2] however, in the era of Geographic information systems, this is far less common than calling it the Geographic coordinate system.