Canonical Combining Class - CCC18

CCC18 is a specific canonical combining class value that indicates a character should be reordered after all characters with a class below 18, but before those with a class above 18, during Unicode normalization. This class is assigned to certain combining marks, such as some Hebrew vowel points and Arabic diacritics, which require particular sequencing relative to other combining signs to preserve correct visual order and semantic meaning. The numeric value 18 places these marks in a middle tier of the combining class hierarchy, ensuring they are not grouped with lower classes like spacing or upper classes like attached above marks. This precise ranking helps prevent ambiguous or incorrect reordering when multiple combining characters are applied to a base character, thereby maintaining consistent text rendering across different systems and fonts.