Hi Mike,
You and Tessa are both correct and I think there's just some miscommunication :)
Basically, an article that is part of a hidden menu (
www.ostraining.com/blog/joomla/how-to-li...r-using-hidden-menu/ ) will not be indexed by Google unless that link is published somewhere publicly accessible at which point Google will eventually index it.
There are two simple things you can do to make it more "hidden".
1) Go to the menu item and the article and set their MetaData Robot's options to "No Index, No Follow". That will tell Google to leave it alone.
2) Archive the articles and in Plugin Manager set the "Search Content" plugin's "Archived Articles" option to "Off". That will tell Joomla to not display the article within Joomla's default search.
Hope this helps!
Kind regards,
Nick