U+324A "㉊" Circled Number Thirty on Black Square Unicode Character

U+324A "㉊" Circled Number Thirty on Black Square is a specialized ideographic symbol used primarily in East Asian contexts, particularly within Japanese and Chinese writing systems, to denote the number thirty enclosed inside a black square with a surrounding circle. It belongs to the Enclosed CJK Letters and Months block and serves as a visual shorthand for indicating the thirtieth item in a sequence, such as on calendars, schedules, list-based documents, or signage. Its design combines clear numeric utility with compact formatting, making it suitable for applications where space is limited and quick numerical identification is needed.