Is there a `hide_all` directive?

I have found that naming a notebook with an underscore first, like _01_more.ipynb will remove a notebook from consideration for the docs.

But is there a way to have a notebook “properly” named, e.g. 01_more.ipynb and control its inclusion into docs using a directive, the same way that skip_exec: true is preventing any cell from being run for nbdev_test?
Note that skip_showdoc still lets the notebook appear in the docs using nbdev_docs or nbdev_preview.

In case, anybody wants to play with a minimal example: GitHub - michaelaye/debug_nbdev