be written. Vowel length may or may not be marked. and may both represent the vowel . or may both represent the consonant . The letter may replace to represent . Carochi's transcription In the 17th century the Jesuit grammarian Horacio Carochi wrote a grammar on the Classical Nahuatl language. For this purpose he developed an orthography for Classical Nahuatl, which was exceptional in that it was the first description of Nahuatl that consistently marked both vowel length and glottal stop (saltillo). His orthography was subsequently used in works and documents by some Jesuits but did not gain wide usage since decrees by Charles II banned the use of indigenous languages in his empire and the later expulsion of the Jesuits from New Spain in 1767. His orthography was further refined by Michel Launey, in his grammar of Classical Nahuatl. The transcription shows vowel length by adding a macron above the long vowel: . Also, it shows saltillo by marking the preceding vowel with a grave accent if it is medial or a circumflex if it is final . Some other transcriptions mark saltillo as an because in Classical Nahuatl, the phoneme was pronounced as a glottal stop and not consistently transcribed by any grammarian except Carochi. Many modern dialects of Nahuatl, however, have as a phoneme instead of saltillo. Historical sources and transcriptions by many modern scholars do not use any standardized transcriptions and usually do not mark vowel length or saltillo at all, and the reader will have to guess or know vowel length and the presence of saltillo. To give an adequate description of Classical Nahuatl, marking both vowel length and saltillo is, however, essential. Contemporary orthography The Secretaría de Educación Pública (Ministry of Public Education) has adopted an alphabet for its bilingual education programs in rural communities in Mexico and this decision has had some influence, even though it is not suited for all dialects of Nahuatl, because of the wide phonological differences between them. The recently established Instituto Nacional de Lenguas Indígenas (National Indigenous Languages Institute, INALI) will also be involved in these issues. This orthography generally does not mark vowel length nor saltillo (but it uses to represent the sound in the dialects that have this sound.) The letter is used for and is written as . Vowels Consonants Notes References Canger, Una. 2002. "An Interactive Dictionary and Text Corpus for Sixteenth- and Seventeenth-Century