U+FD21 "ﴡ" Arabic Ligature Sad with Alef Maksura Final Form Unicode Character

U+FD21 "ﴡ" Arabic Ligature Sad with Alef Maksura Final Form is a typographic ligature used in the Arabic script, specifically representing the combined forms of the letter Sad (ص) and the letter Alef Maksura (ى) when they appear together at the end of a word. This character belongs to the Arabic Presentation Forms-A block, which encodes precomposed ligatures designed to support calligraphic and typographic traditions where two characters are fused into a single glyph for aesthetic or readability reasons. Its use is primarily historical or stylistic, as modern digital text often relies on dynamic shaping by rendering engines rather than such precomposed forms.