Devanagari Vowel Sign Uu (U+03AE) is a Unicode nonspacing mark from the Devanagari block. It resides on Plane 0 (BMP, Basic 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 ू.