tt(TYPEOUT) requires one argument. The text of the list is sent to the
standard error stream, followed by a newline. This feature can be handy to
show, e.g., messages such as version numbers in macro package files.

Example: The following macro includes a file and writes to the screen that
this file is currently processed.
        verb(
    DEFINEMACRO(includefile)(1)(
        TYPEOUT(About to process document: ARG1)
        INCLUDEFILE(ARG1)
    )
        )

