Hello, I am wondering how U+02B9 MOFIFIER LETTER PRIME made its way into the Unicode repertoire, and how it acquired its comment “transliteration of mjagkij znak (Cyrillic soft sign: palatalization)“.
ISO/R 9:1954 through ISO/R 9:1986 map the mjagkij znak “ь” to the apostrophe, and so does DIN 1460:1982. The latter clearly depicts the apostrophe that later became U+02BC, while I am not sure whether also ISO/R 9 does so or rather depicts a glyph like U+0027. (All of these standards predate Unicode, so they just depict glyphs.) ISO/R 9:1995 maps the mjagkij znak “ь” to the prime, particularly to the modifier letter U+02B9, in accordance with the comment in the Unicode charts. Unicode archeologists, can you shed some light on the history of both U+02B9 and the mjagkij znak? And linguists, can you tell me how the mjagkij znak is transliterated normally, as an apostrophe or as a prime? Thanks for any comments, Otto