U+3349 "㍉" Square Miri Unicode Character

U+3349 "㍉" Square Miri is a CJK (Chinese, Japanese, and Korean) compatibility ideograph that represents the metric prefix "milli" combined with the character for "meter," forming a single square glyph used primarily in Japanese typography to denote the unit of length known as a millimeter. This character belongs to the CJK Compatibility block and was encoded for compatibility with pre existing character sets and legacy text, allowing it to appear as a compact, square shaped symbol in East Asian writing systems. It is still sometimes used in contexts like technical documents, labels, or signage where space is limited, though modern Japanese increasingly uses the separate characters "ミリメートル" or the more standard "mm" for millimeter.