replace the dot over the lowercase i, whereas in a language like Vietnamese, the acute tone mark is added above the dot. Diacritic signs for alphabets considered independent may be encoded separately, such as the acute ("tonos") for the Greek alphabet at U+0384, and for the Armenian alphabet at U+055B. Some Cyrillic-based alphabets (such as Russian) also use the acute accent, but there is no "Cyrillic acute" encoded separately and U+0301 should be used for Cyrillic as well as Latin (see Cyrillic characters in Unicode). The point that the same grapheme can have many "meanings" is even more obvious considering e.g. the letter U, which has entirely different phonemic referents in the various languages that use it in their orthographies (English etc., French , German , etc., not to mention various uses of U as a symbol). Compatibility issues CJK fullwidth forms In traditional Chinese character encodings, characters usually took either a single byte (known as halfwidth) or two bytes (known as fullwidth). Characters that took a single byte were generally displayed at half the width of those that took two bytes. Some characters such as the Latin alphabet were available in both halfwidth and fullwidth versions. As the halfwidth versions were more commonly used, they were generally the ones mapped to the standard code points for those characters. Therefore a separate section was needed for the fullwidth forms to preserve the distinction. Letterlike symbols In some cases, specific graphemes have acquired a specialized symbolic or technical meaning separate from their original function. A prominent example is the Greek letter π which is widely recognized as the symbol for the mathematical constant of a circle's circumference divided by its diameter even by people not literate in Greek. Several variants of the entire Greek and Latin alphabets specifically for use as mathematical symbols are encoded in the Mathematical Alphanumeric Symbols range. This range disambiguates characters that would usually be considered font variants but are encoded separately because of widespread use of font variants (e.g. L vs. "script L" vs. "blackletter L" vs. "boldface blackletter L" ) as distinctive mathematical symbols. It is intended for use only in mathematical or technical notation, not use in non-technical text. List , Greek Many Greek letters are used as technical symbols. All of the Greek letters are encoded in the Greek section of Unicode but many are encoded a second time under the name of