CID (Character Identifier) fonts are used for large character sets (e.g., Chinese, Japanese, Korean – CJK).
| Issue | Solution |
|-------|----------|
| F1 appears in PDF text | Missing embedded font → re-export PDF with embedding |
| F1 in print output | Install original font or map F1 to a readable font |
| F1/F2/F3/F4 in Ghostscript | Create custom Fontmap.GS with (F1) /NotoSansCJK-Regular |
| Want to avoid substitution | Convert all text to outlines (last resort) | cid font f1 f2 f3 f4 better
While the numbers are arbitrary (they simply count fonts), they often correlate with the order of appearance or role of the font in a structured document. Here is how advanced users interpret them to build better workflows: CID (Character Identifier) fonts are used for large