As of 2025, the industry is moving toward OpenType (CFF2 and TrueType collections). However, PDF 2.0 still supports CID-keyed fonts for backward compatibility. The "F1 Family" persists primarily in two places:

: A "Character Map" (CMap) file is used to translate encoded strings in a document into these specific CID numbers. Why You See "CIDFont F1"

Common scenarios where you encounter "F1 Family":

The CID (Character ID) font F1 family is a type of font used in PostScript and PDF documents. It is a composite font, which means it is a font that contains multiple font resources, each with its own character set. The CID font F1 family is one of the many font families used in the Adobe CID font system.