ps-print-prologue-header

ps-print-prologue-header is a variable defined in `ps-print.el'.
Its value is

nil

Documentation:
PostScript prologue header comments besides that ps-print generates.

`ps-print-prologue-header' may be a string or a symbol function which returns a
string. Note that this string is inserted on PostScript prologue header
section which is used to define some document characteristic through PostScript
special comments, like "%%Requirements: jog\n".

ps-print always inserts the %%Requirements: comment, so if you need to insert
more requirements put them first in `ps-print-prologue-header' using the
"%%+" comment. For example, if you need to set numcopies to 3 and jog on
requirements and set %%LanguageLevel: to 2, do:

(setq ps-print-prologue-header
"%%+ numcopies(3) jog\n%%LanguageLevel: 2\n")

The duplex requirement is inserted by ps-print (see `ps-spool-duplex').

Do not forget to terminate the string with "\n".

For more information about PostScript document comments, see:
PostScript Language Reference Manual (2nd edition)
Adobe Systems Incorporated
Appendix G: Document Structuring Conventions -- Version 3.0

You can customize this variable.

This variable was introduced, or its default value was changed, in version 20 of Emacs.