x21D4

x21D4 is a Unicode character with the hexadecimal code point U+21D4. It is represented visually as a stylized depiction of the Roman numeral "IV," resembling a crossed-out or "invalid" symbol. The character is classified under the "Number Forms" block in the Unicode Standard, which includes various numeric symbols and representations.

Originally introduced in Unicode version 1.1 in 1993, x21D4 is commonly used in contexts where crossed-out or invalid numerals are needed. It is frequently employed in mathematical, financial, or educational materials to indicate an incorrect or canceled value, such as a crossed-out price tag or an erased number. The symbol is also sometimes used in typography or design to convey a sense of negation or prohibition related to numerical values.

While not widely recognized as a standalone symbol in everyday language, x21D4 serves a functional purpose in specific technical and formal applications. Its usage is less common compared to other Unicode characters, such as the crossed-out zero (⊗) or crossed-out circle (⊗), but it remains a useful tool for designers and writers requiring a distinct visual representation of an invalid numeral. The character can be accessed via its Unicode code point or through input methods that support Unicode input.