I'm a bit confused about the description in the 3 Stylesheets and Scripts section of the project page.

The last line says:

Passing cssOut and jsOut will write the respective files to disk at the given path.

From my understanding, exporting the stylesheets and scripts to a separate directory is done using the assets=external and assets-dir=dir-name options. So, what exactly do cssOut and jsOut refer to in this context?