Unicode Block - CJK Compatibility

CJK Compatibility is a collection of precomposed characters and square-form symbols that were originally included to preserve the exact glyph shapes used in legacy East Asian character sets, particularly for vertical text layout and for representing units, dates, and other common expressions in a single character space. It contains items like the Japanese era names such as Meiji and Showa, circled or parenthesized ideographs, and square abbreviations for units of measurement like square meter or kilogram, as well as Roman numerals and other miscellaneous symbols that are frequently used in Japanese, Chinese, and Korean typography. While many of these characters have since been unified with regular CJK ideographs or other Unicode characters, this set still serves to maintain compatibility with older systems and to allow exact round-trip conversion from legacy encodings without loss of formatting information.