1. R. Jakobson, G. Pant, and M. Halle, Preliminaries to Speech Analysis (Cambridge, 1952), p. 42.
2. Thus, e.g., the regularity of vowel harmony in Turkish is obscured by the presence of a large number of Arabic and Persian loan words which do not show vowel harmony. R. Lees, The Phonology of Modern Standard Turkish (Indiana University Publications, Vol. 6 of the Ural and Altaic Series, The Hague, 1961), p. 14, is certainly correct in requiring a “diacritic” to distinguish native from borrowed morphemes. In Finnish, the harmony is obscured not only by foreign loans but also by certain suffixes which must be specially treated; cf., e.g., the suffix-lainenwith graveain bothtuollainen‘that kind of’ andtuollinen(sub-standardtälläineri)‘this kind of’.
3. This method of describing vowel harmony is used in standard works on Classical Mongolian; see, e.g. N. Poppe,Grammar of Written Mongolian(Wiesbaden, 1954), K. Grønbech and J. Krueger,An Introduction to Classical (Literary) Mongolian(Wiesbaden, 1955). N. Trubetzkoy,Grundzüge der Phonologie(Göttingen, 1958) used this method to describe vowel harmony in Mongolian (p. 104), in Finno-Ugric and Turkic languages (pp. 88, 93, 95), and in other languages such as Ibo, Lambda, etc. (pp. 250–251).