Joining Group - Sad

Sad is a special value indicating that a character does not participate in cursive joining behavior, meaning it never connects to adjacent letters in scripts like Arabic or Syriac. This value applies to characters that are inherently non joining, such as spaces, punctuation, digits, and most Latin or Cyrillic letters, even when they appear within a joining script context. It signifies that the character acts as a barrier, preventing any cursive connection between letters on either side of it, and it does not take on contextual forms like initial, medial, or final shapes. In practical terms, any character assigned this value remains visually isolated in rendered text, with no ligature or connecting stroke to its neighbors, regardless of its position in a word. This is distinct from values that allow conditional joining, as Sad is absolute and unchanging for the character it describes.