There are two escapes which give information directly to the postprocessor. This is particularly useful for embedding PostScript into the final document.
devicerequest simply processes its argument in copy mode (see Copy-in Mode).
‘use_charnames_in_special’ is currently used by
This is approximately equivalent to ‘\X'\*[name]'’ (one-character name n, two-character name nm). However, the contents of the string or macro name are not interpreted; also it is permitted for name to have been defined as a macro and thus contain newlines (it is not permitted for the argument to
\Xto contain newlines). The inclusion of newlines requires an extension to the UNIX
troffoutput format, and confuses drivers that do not know about this extension (see Device Control Commands).
See Output Devices.