Arabic Diacritics - I'jam (phonetic Distinctions of Consonants)

I'jam (phonetic Distinctions of Consonants)

The ijam ⟨إِعْجَام⟩ (ʾiʿǧām) are the pointing diacritics that distinguish various consonants that have the same form (rasm), such as ⟨ـبـ⟩ /b/, ⟨ـتـ⟩ /t/, ⟨ـثـ⟩ /θ/, ⟨ـنـ⟩ /n/, and ⟨ـيـ⟩ /j/. Typically ijam are not considered diacritics but part of the letter.

Early manuscripts of the Qurʾān did not use diacritics either for vowels or to distinguish the different values of the rasm. Vowel pointing was introduced first, as a red dot placed above, below, or beside the rasm, and later consonant pointing was introduced, as thin, short black single or multiple dashes placed above or below the rasm (image). These ijam became black dots about the same time as the ḥarakat became small black letters or strokes.

Typically, Egyptians do not use dots under final yāʾ ⟨ي⟩, both in handwriting and in print, as ʾalif maqṣūrah ⟨ى⟩. This practice is also used in copies of the muṣḥaf (Qurʾān) scribed by ʿUṯman Ṭaha. The same unification of yāʾ and ʾalif maqṣūrā has happened in Persian, resulting in what The Unicode Standard calls "arabic letter farsi yeh", that looks exactly the same as yāʾ in initial and medial forms, but exactly the same as ʾalif maqṣūrā in final and isolated forms ⟨یـ ـیـ ـی⟩.