them from tone numbers; tone 3 in Mandarin Chinese, for example, is not mid /3/. However, it is not necessary with tone letters, so /33/ = or simply . If a distinction is made, it may be that is mid tone in a register system and is mid level tone in a contour system, or may be mid tone on a short syllable or a mid checked tone, while is mid tone on a long syllable or a mid unchecked tone. IPA diacritic notation is also sometimes seen for Chinese. One reason it is not more widespread is that only two contour tones, rising and falling , are widely supported by IPA fonts while several Chinese varieties have more than one rising or falling tone. One common workaround is to retain standard IPA and for high-rising (e.g. ) and high-falling (e.g. ) tones and to use the subscript diacritics and for low-rising (e.g. ) and low-falling (e.g. ) tones. North America Several North American languages have tone, one of which is Cherokee, an Iroquoian language. Oklahoma Cherokee has six tones (1 low, 2 medium, 3 high, 4 very high, 5 rising and 6 falling). The Tanoan languages have tone as well. For instance, Kiowa has three tones (high, low, falling), while Jemez has four (high, mid, low, and falling). In Mesoamericanist linguistics, /1/ stands for high tone and /5/ stands for low tone, except in Oto-Manguean languages for which /1/ may be low tone and /3/ high tone. It is also common to see acute accents for high tone and grave accents for low tone and combinations of these for contour tones. Several popular orthographies use or after a vowel to indicate low tone. The Southern Athabascan languages that include the Navajo and Apache languages are tonal, and are analyzed as having two tones: high and low. One variety of Hopi has developed tone, as has the Cheyenne language. Tone orthographies In Roman script orthographies, a number of approaches are used. Diacritics are common, as in pinyin, but they tend to be omitted. Thai uses a combination of redundant consonants and diacritics. Tone letters may also be used, for example in Hmong RPA and several minority languages in China. Tone may simply be ignored, as is possible even for highly tonal languages: for example, the Chinese navy has successfully used toneless pinyin in government telegraph communications for decades. Likewise, Chinese