U+3390 "㎐" Square Hz Unicode Character

U+3390 "㎐" Square Hz is a precomposed CJK compatibility ideograph that represents the unit of frequency "hertz" in a square format, specifically designed for efficient display in East Asian text environments where space is limited. It encodes the Latin letter "H" and "z" combined into a single glyph, matching the appearance of "Hz" enclosed within a square shape to fit neatly alongside other squared unit symbols like "㎏" (kilogram) or "㎝" (centimeter). Although it is classified under the CJK Compatibility block, its primary purpose is to maintain visual consistency in vertical writing and grid layouts, and it corresponds to the standard unit hertz, which measures cycles per second in physics and engineering contexts.