Either documentation or code is wrong about the "clean" command option to disable prompt before removing files.

Documentation says:
<pre>
$ fossil help clean
Usage: fossil clean ?--force? ?--dotfiles?
...
You will be prompted before removing each file. If you are
sure you wish to remove all "extra" files you can specify the
optional --force flag and no prmpts will be issued.
</pre>

However, --force doesn't work (Fossil asks before removing files). Code in <code>checkin.c</code> ([2e4a6e1c0f]) says it wants "--all" option:

<pre>
  allFlag = find_option("all","a",0)!=0;
</pre>

And "--all" option actually works.

So either code or documentation needs to be updated.