Tasmota Script example use of "%/file" and more...

[Derek-K]

I have been trying to figure how to use the "%/file" option, according the the doc
%/file calls a file from the file system and send its content to browser. in this file any cmds may apply.

Is there any example? And what does "any cmds may apply", does it mean a file can contain script commands? (e.g. bu, ck etc...?)

Also, is it possible to have a custom "sub-menu" screen generated using script, it doesn't matter if it is actually a separate page or a collapsible section on main page. (But prefer not showing the full "sub-menu" on main screen because it takes up too much space. Mainly I wanted to move all the custom options on a separate page for cleaner look)

Finally, I can't figure out what's the use for wcs, wcf and wfs. Seems like what I have under >W section is already displaying.

Thanks.