Code point
U+22FF
Glyph appearance depends on your fonts.
U+22FF
SmU+22FF Z NOTATION BAG MEMBERSHIP is a Unicode 16.0.0 character in the Math Symbol category. It belongs to the Mathematical Operators block.
Choose the representation you need, then copy its value.
U+22FF
8959
⋿
⋿
E2 8B BF
22FF
000022FF
%E2%8B%BF
\u22FF
\u22FF
\u22FF
\22FF