Indic Positional Category - Overstruck

Overstruck is a value indicating that a character in Indic scripts is positioned over another base character, rather than following it in a linear sequence. This typically applies to vowel signs or diacritical marks, such as the Malayalam vowel sign U, which are rendered above the consonant they modify. The overstruck position is distinct from pre-base, post-base, or below-base placements, and it affects how the shaping engine orders the visual stacking of glyphs. This categorization helps ensure correct rendering in complex text layouts, where the mark overlays the core letter without altering the underlying character order. It is crucial for accurate display in languages that use such vertically combined forms.