Cidfont -

The acronym stands for Character Identifier . Unlike standard fonts where characters are accessed via "glyph names" (like /A or /arrowleft ) or simple numeric indices, CIDFonts access characters via a numeric identifier known as a CID .

Standard font encodings (like WinAnsiEncoding ) are limited in how many characters they can address. CIDFonts, by utilizing a CMap, can support character sets of practically unlimited size. This made them the de facto standard for CJK publishing, allowing a single font resource to contain every necessary character without running out of "slots." cidfont

The "CID" in CIDFont stands for . The system separates the character's identity from its visual representation. Here is the typical hierarchy: The acronym stands for Character Identifier

| Aspect | Traditional Type 1 Font | CID-Keyed Font | | :--- | :--- | :--- | | | 256 | 65,535+ | | Encoding Support | Single (hard-coded) | Multiple (via CMap) | | File Management | Many files per font family | One file | | Use Case | Western alphabets | CJK, Unicode, Large symbol sets | | Modern Support | Legacy (deprecated) | Full (via OpenType/CFF) | CIDFonts, by utilizing a CMap, can support character

This usually happens when a PDF is created without embedding the font. If the viewing computer doesn't have the specific CID resource installed, the text may turn into "tofu" (empty boxes) or gibberish.