SQUARE WITH TOP HALF BLACK U+2B12

BlockMiscellaneous Symbols and Arrows
CategoryOther Symbol
UTF-80xE2 0xAC 0x92
UTF-160xFF 0xFE 0x12 0x2B
UTF-320xFF 0xFE 0x0 0x0 0x12 0x2B 0x0 0x0
HTML⬒
Pythonu"\u2B12"