Linked from
The 25 pages that link to Abjad, each with the reason it gives.
AramaicRelated: Aramaic writing generally records consonants rather than fully spelling every vowel.
WritingRelated: Abjads show that writing can represent language while omitting many vowel sounds.
Arabic diacriticsRelated: Arabic’s usual omission of short vowels reflects its abjad structure.
DiacriticRelated: Many abjads can omit vowel diacritics in ordinary text and add them for clarity.