Stigma (letter) sigma form ς never occurs inside a word and is never used as a numeral either. Uppercase forms of stigma as a numeral (Ϛ) are rare in practice; when they occur, they can often be confused with uppercase forms of another numeral symbol, koppa (Ϟϟ), which stands for 90. Stigma is encoded in Unicode as "Greek letter stigma" U+03DA (Ϛ) and "Greek small letter stigma" U+03DB (ϛ). Stigma (letter) Stigma (ϛ) is a ligature of the Greek letters sigma (Σ) and tau (Τ), which was used in writing Greek between the Middle Ages and the 19th century. It is also
Metrication in the United States SI is widespread for many applications. Residential electric power plans use kilowatt hours. The luminous flux from lamps is specified in lumens rather than candlepower. The letter "K" is commonly used to denote "thousand" (e.g., "She earns $80K"), even though this is inconsistent with the lowercase "k" in SI. This usage has largely replaced the letter "G" (for "grand", used almost exclusively for money) and the Roman numeral "M" that was commonly used for "thousand" before the 1960s; in fact, the "M" has now come to denote "million" (e.g., "$32.5M budget"). Televised and radio weather reports are given in degrees