Vietnamese Alternate Reading Mark Ca (U+16FF0) is a Unicode spacing combining mark from the Ideographic Symbols and Punctuation block. It resides on Plane 1 (SMP, Supplementary Multilingual Plane), has bidirectional class L (left-to-right), is not mirrored, and has combining class 6 (Han Reading). In HTML it can be written as 𖿰 or 𖿰. Because it is outside the Basic Multilingual Plane, proper font support is required; otherwise a fallback box may be shown.