stands for Character ID. CID fonts are a type of font used in PostScript and PDF files, designed to handle large character sets efficiently, such as those required for Asian languages (Chinese, Japanese, Korean, etc.). Unlike traditional Type 1 fonts or TrueType fonts, which are limited to 256 characters, CID fonts can define thousands of characters.
✦ CIDFonts were revolutionary for handling large character sets like Chinese, Japanese, and Korean (CJK), where a simple byte-to-glyph mapping isn't enough. cidfont+f1 font