This article summarizes the development of the Tanacross practical orthography, highlighting the crucial differences between practical and technical orthography used in some linguistic publications. Three stages of Tanacross orthography are exemplified in research from the 1980s. A fourth stage is a hybrid of the second and third stages, incorporating the vowel system and tri-graph dental affricates of the third stage but without distinguishing semi-voiced fricatives with underscore. A fifth stage, exemplified in publications of the Yukon Native Language Centre, adds five types of vowel tone markings. This system recognizes three distinctions in fricative voicing. The vowel system uses five vowel symbols to represent six phonemic vowels. Each vowel symbol may occur alone or in a sequence of identical symbols. Tone is marked on vowels using a diacritic. Low tone syllables are not marked for tone. Only the first of a sequence of orthographic vowels is marked for tone. Nasalization is marked with the Americanist nasal hook. Both vowels of a vowel sequence are marked with the nasal hook if the vowel is nasalized. Glottal stop is not written in word-initial position. Words spelled with an initial vowel actually begin with a glottal stop. (SM)