#process-output identifies the default output destination provided to OmniMark by the system.
In earlier releases of OmniMark,
#process-output was called
#console; although this
keyword can still be used to perform the same function, its use is deprecated.
declare #process-output has declarations can be used to change some of the characteristics of
#process-output stream. Note that
#process-output never allows referents, so to declare that this stream has
referents-not-allowed is an error.