The PDF generator only included the characters necessary for that specific document to reduce file size.

Traditional fonts are limited to 256 characters. CID fonts bypass this limit by using an index of numbers (CIDs) to map out and display tens of thousands of glyphs. Today, this technology is also widely used in standard PDF creation to subset fonts, keeping file sizes small while maintaining visual layout consistency. Decoding the Labels: F1, F2, F3, and F4