Palatalization in Church Slavonic Texts of the Ustav Era

In South Slavic manuscripts of the Ustav Era, there are eight characters (all consonants) which can be softened or “palatalized”, and they are divided into two functionally different groups (the upper case forms are all unattested):

Group 1: Д, Л, М, Н, Р. The first three of these have been properly encoded into the Unicode Standard. The fourth letter can be typset by adapting a modern ligature from one of the non-Slavic language groups using Cyrillic script (although this is technically incorrect and needs to be resolved properly). The fifth letter has not yet been encoded in the Standard. All five of these characters can be found in two forms in period manuscripts: i) as separate characters (digraphs consisting of character + palatalization diacritic), and ii) as composites (ligated characters). The composite ligature forms are exactly equivalent to the digraph forms. (NOTE: The ligated forms are not "character + Г", but "character + palatalization mark".) Although the Unicode Standard does not indicate that the ligated soft consonants have canonical decomposition, they should be decomposable.

Group 2: Г, К, Х. These three letters (coincidentally matching the same character group in Greek?) only have separate digraph forms (character + diacritic). Composite forms are sometimes seen in older legacy fonts, but these ligatures are unattested. The palatalization mark also has a different linguistic value from the Group 1 usage.

GROUP 1
GROUP 2
separate characters (digraphs consisting of character + palatalization diacritic)
д҄
л҄
м҄
н҄
р҄
г҄
к҄
х҄
composite characters (ligated)
Ꙣꙣ
Ꙥꙥ
Ꙧꙧ
Ҥҥ
[--]

The combining palatalization mark (Unicode point 0484) is not used in the printed tradition of Church Slavonic, but is a character belonging solely to the South Ustav manuscript tradition and in technical transcriptions (especially modern transliterations). It can be transliterated as “j” (Eastern European usage), and it represents the beginning of a diphthong or a softening of a consonant.

— Source: Handbuch der altbulgarischen (altkirchenslavischen) Sprache, von A. Leskien (Weimar, 1898) [PDF, courtesy of Google Books]