Using a Placeholder as a Ditto Parameter.

I’m losing brain-cells as I get older apparently.  Isn’t this call supposed to be able to work?

[[Ditto? &parents=`6` &documents=`[+featured_item+]` &noResults=` ` &tpl=`featured_trans` ]]

The place-holder variable works - as I can see it has a value when I display it on a the screen.

I’ve also tried [! !] - which also fails.

Any ideas?

Thanks
codedoc

Try [*featured_item*]

[+ +] are mostly used inside of template chunks, in the document use [* *] to access the placeholders.