Siddham Vowel Sign Uu (U+115B3) is a Unicode nonspacing mark from the Siddham block. It resides on Plane 1 (SMP, Supplementary Multilingual Plane), has bidirectional class NSM (nonspacing mark), is not mirrored, and has combining class 0 (Not Reordered). In HTML it can be written as 𑖳 or 𑖳. Because it is outside the Basic Multilingual Plane, proper font support is required; otherwise a fallback box may be shown.