Canonical Combining Class - CCC20

CCC20 is a numeric value assigned to certain diacritical marks and spacing characters that indicates a specific level of reordering priority when combining marks are processed during text normalization. Marks with CCC20 are treated as attached above or below the base character, meaning they are positioned vertically relative to the glyph, and they are applied after any marks with a lower class number but before those with a higher one, such as those in the 230s that sit above with distinct stacking rules. This class helps ensure consistent canonical ordering for sequences like vowel signs or tone marks, where the relative position of the mark influences its combining behavior. Practically, CCC20 is used for marks that are neither fixed to the left or right nor strictly superscript or subscript, but that still attach to the base in a predictable vertical manner, ensuring that text renders and normalizes correctly across different systems.