Need to get my head around this. It looks like we have the two items below IF we have sub-menus eg Article Manager, Article Manager: Article, Article Manager:Categories
But it's not consistent
Sometimes we use the word Manager and sometimes we don't. As with everything we must be consistent.
Proposal to remove the word Manager from Joomla!
Sometimes we use the colon eg Article Manager: Articles Sometimes we don't eg Article Manager Options
There is often a mismatch between the label used for a menu item in the drop down and the label used in the sidebar.