How to access item name as property

[kwin]

There should be an example on how to access the value given in either

• items->item
• itemsWithProperties->itemWithProperty->name or
• content (the current value of the comma-separated list)

as a property from the downstream project (if you use goal invoker). Also it is not completely clear from the documentation where placeholders like @item@ are getting replaced (I guess only within the plugin configuration of this plugin).