Unlike simple fonts (Type 1 or TrueType) that use an 8-bit encoding (max 256 characters), CID-keyed fonts are designed for large character sets—essential for languages like Chinese, Japanese, and Korean (CJK). A CIDFont is a type of composite font that maps a CID (an integer) to a glyph description.
In PDF syntax, a CIDFont dictionary is a subtype of the Font dictionary. When you see CIDFontType0 or CIDFontType2 , you are looking at a placeholder for thousands of possible glyphs. The labels F1 , F2 , etc., are not standard font names like "Arial" or "Times New Roman". Instead, they are font resource name tags automatically generated by PDF creation libraries (such as iText, Apache PDFBox, or Adobe Acrobat’s own engine). cidfontf1 f2 f3 f4 f5 f6 updated
For years, these labels have confused developers and document analysts. But what are they exactly? Why do they appear in your PDF structure? And most importantly, what has changed in the specifications for these font dictionaries? Unlike simple fonts (Type 1 or TrueType) that