This is a format for presenting fonts in PDF files that was initially conceived to store symbols in the Japanese and Chinese languages because it had a 16-bit structure and allowed for more precise adjustment. CID expands the the potential for PostScript by supporting languages that do not have a left-to-right orientation, and by supporting even a vertical mode of orientation.
This is a format for storing and presenting text information. It’s also referred to as CID 2 and is basically used for imaging and creating complex fonts in PDF. It’s based on the TrueType system, but allows for more precise adjustment and allows for refined writing due to a 16-bit structure that is very important when displaying Asian language symbols.