Code point
U+2B15
Glyph appearance depends on your fonts.
U+2B15
SoU+2B15 SQUARE WITH LOWER LEFT DIAGONAL HALF BLACK is a Unicode 16.0.0 character in the Other Symbol category. It belongs to the Miscellaneous Symbols and Arrows block.
Choose the representation you need, then copy its value.
U+2B15
11029
⬕
⬕
E2 AC 95
2B15
00002B15
%E2%AC%95
\u2B15
\u2B15
\u2B15
\2B15