Special Fonts (The GNU Troff Manual)

#### 5.19.6 Special Fonts

Special fonts are those that `gtroff` searches when it cannot find the requested glyph in the current font. The Symbol font is usually a special font.

`gtroff` provides the following two requests to add more special fonts. See Using Symbols, for a detailed description of the glyph searching mechanism in `gtroff`.

Usually, only non-TTY devices have special fonts.

Request: `.special` [s1 s2 …] ¶
Request: `.fspecial` f [s1 s2 …] ¶

  Use the `special` request to define special fonts. Initially, this list is empty.

  Use the `fspecial` request to designate special fonts only when font f is active. Initially, this list is empty.

  Previous calls to `special` or `fspecial` are overwritten; without arguments, the particular list of special fonts is set to empty. Special fonts are searched in the order they appear as arguments.

  All fonts that appear in a call to `special` or `fspecial` are loaded.

  See Using Symbols, for the exact search order of glyphs.