In the world of PDFs, "CID" stands for . CID-keyed fonts are a sophisticated technology developed by Adobe to handle large, complex character sets—specifically for East Asian languages like Chinese, Japanese, and Korean (CJK).
The labels are internal placeholders or "shorthand" names generated by software (like InDesign, Illustrator, or Acrobat Distiller) during the PDF export process. Cid Font F1 F2 F3 F4 Free Download
If you extracted a page from a larger document, the font "map" (CMap) might have been lost. In the world of PDFs, "CID" stands for