: If your computer doesn't have the original font the PDF was built with, it may fail to find "Cidfont-f1" and display dots or garbage text instead. Common Mappings
/Cidfont-f1 /SourceHanSans-Regular (Adobe Japan1) ; /Cidfont-f2 /SourceHanSerif-Regular (Adobe Japan1) ; /Cidfont-f3 /SourceHanSans-Regular (Adobe GB1) ; /Cidfont-f4 /SourceHanSerif-Regular (Adobe GB1) ; /Cidfont-f5 /SourceHanSans-Regular (Adobe Korea1) ; /Cidfont-f6 /SourceHanSerif-Regular (Adobe Korea1) ; Cidfont-f1 F2 F3 F4 F5 F6
The font CIDFont+F1 is Arial (blod) and CIDFont+F2 is Arial (Regular) PDFont - PDF Library API Reference - Adobe Open Source : If your computer doesn't have the original
On older macOS systems (Classic OS 9 or early OS X), data fork fonts (DFONT) sometimes exposed internal resources as f1 , f2 , etc. A corrupt DFONT containing CID resources might list its suite as: /Cidfont-f2 /SourceHanSerif-Regular (Adobe Japan1)