U+3351 "㍑" Square Rittoru Unicode Character

U+3351 "㍑" Square Rittoru is a precomposed CJK Compatibility Ideograph used primarily in East Asian typography to represent the unit of volume "liter" (rittoru) in a compact square format. This character was included in Unicode to maintain roundtrip compatibility with older Japanese character encodings, where such squared forms were common in vertical text or constrained spaces. It visually combines the katakana "リ" (ri) and "ットル" (ttoru) into a single block, though its use in modern digital text is rare and generally discouraged in favor of the standard "L" or "ℓ" symbols.