Cid Font F1 F2 — F3 F4

First, it is necessary to establish the foundational concept of a CID-keyed font. Unlike traditional fonts that rely on a single-byte encoding (e.g., ASCII for Latin fonts), a CID font separates the character collection from the glyph descriptions. A is a number that identifies a character, not its visual representation. A CMap (Character Map) then translates between an external encoding (like Shift-JIS or Unicode) and these internal CIDs. The "F" designators—F1 through F4—are specific data structures or processing states within the Adobe Type Manager and PostScript rendering engines that facilitate this mapping and glyph retrieval process.

: Check the document properties (Ctrl+D or File > Properties > Fonts) to see if the original font names are listed next to the CID labels. cid font f1 f2 f3 f4

This abstraction allows the PDF to remain small and efficient. The actual font name (PostScript name) is stored one level deeper, inside the CIDFont dictionary. First, it is necessary to establish the foundational