U+115BB "𑖻" Siddham Vowel Sign Au Unicode Character

U+115BB "𑖻" Siddham Vowel Sign Au is a combining diacritical mark used in the Siddham script, an ancient writing system historically employed for sacred Buddhist texts in India, China, and Japan. This vowel sign modifies a consonant character by adding the "au" vowel sound, specifically representing a diphthong equivalent to the "ou" sound in English words like "loud". In Siddham orthography, it is positioned after the consonant base form, reflecting the abugida nature of the script where vowels are indicated through modifying marks rather than independent letters. The character belongs to the Siddham block of the Unicode Standard, which was added to preserve and digitally encode this historically significant script.