Greek Instrumental Notation Symbol-18 (U+1D228) is a Unicode other symbol from the Ancient Greek Musical Notation block. It resides on Plane 1 (SMP, Supplementary Multilingual Plane), has bidirectional class ON (other neutrals), 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.