Indic Syllabic Category - Tone Letter

Tone Letter is a value that classifies characters used exclusively to denote tones in writing systems, typically for languages like Chinese, Vietnamese, or certain African and Southeast Asian scripts. These characters, such as tone marks or modifier letters, do not represent consonants or vowels but are essential for indicating pitch contours that change word meaning. The value distinguishes them from other syllable-related categories, ensuring that rendering engines and text processing tools treat them appropriately, such as applying correct spacing, line breaking, or phonetic transcription. It helps maintain linguistic accuracy in digital text by isolating a functional subset of symbols that operate as suprasegmental cues rather than core syllabic components.