Registry-Ordering: Adobe-GB1
Primary Use: Simplified Chinese as used in mainland China and Singapore.
CIDFonts natively support vertical writing (V) variants. For F1 (Japanese), a CMap ending in -V (e.g., 90pv-RKSJ-V) rotates and reorders glyphs for vertical text layout. F2, F3, and F4 also have vertical variants, though less common. cidfont f1 f2 f3 f4 f5 f6 full
Adobe defined six primary character collections based on the script and region. Each collection has a unique Registry and Ordering string (e.g., Adobe-Japan1). The "F" number is an internal shorthand for these collections. F2, F3, and F4 also have vertical variants,
Cause: You edited a text string that uses CIDFont+F2, but your system does not have the original base font installed. The PDF viewer falls back to a different F-slot.
Fix: Extract the embedded font using tools like pdftops (Xpdf suite): pdftops -fontdir ./extracted_fonts document.pdf The "F" number is an internal shorthand for