A heptagraph is a sequence of seven letters used to represent a single sound (phoneme), or a combination of sounds, that do not correspond to the individual values of the letters. Heptagraphs are extremely rare. Morse code uses 2 heptagraph: , for the dollar sign; and , for the letter Ś. Most other fixed sequences of seven letters are composed of shorter multigraphs with a predictable result. The seven-letter German sequence , used to transliterate the Russian and Ukrainian letter , as in for Russian/Ukrainian (R. pronunciation , Ukr. pronunciation ) "borscht", is a sequence of a trigraph and a tetragraph . Likewise, the Juu languages have been claimed to have a heptagraph , but this is also a sequence, of and . See also Multigraph (orthography) Digraph (orthography) Pentagraph Hexagraph References 7