Ahom Vowel Sign Ai (U+2DD1) is a Unicode nonspacing mark from the Ahom 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 𑜩.