A special double-triangle colon symbol is used in IPA to indicate that the preceding sound is long. Its form is that of two triangles, each a bit larger than a point of a standard colon, pointing toward each other. It is available in Unicode as modifier letter triangular colon, Unicode U+02D0 (). A regular colon is often used as a fallback when this character is not available, or in the practical orthography of some languages (particularly in Mexico), which have a phonemic long/short distinction in vowels.