ref: a08bf6831f5122fc9bfc6dccf77096f6ac2e4d03
dir: /sys/lib/troff/font/devutf/charlib/README/
Postscript definitions for special troff characters. File names are the two character troff names. Each defines a PostScript procedure that begins with build_ and ends with the character's name. The build_?? procedure is called with the character width as it's only argument. The .map files contain extra character data (e.g. image data) that dpost downloads immediately after the build_?? call, if the character's font table code field is 2 (rather than 1). The following PostScript variables are available: font current font ptsize current point size size actual font size - scaled up from ptsize Don't overuse this stuff!