I mistakenly hid the interface while looking at a map then switched to something else (probably world view). When I came back to the map I noticed the interface missing and I needed to rotate and zoom. I looked everywhere and saw no clue on how to restore the map interface. Not knowing what to do I pressed all the function keys then letters then other keys and finally pressed tab which restored the map interface.
I suggest you leave an icon when hiding the the map interface. A common icon when something his hidden is a slim rectangle on the display edge with rounded corners toward the center as well as an arrowhead at its center pointing toward the display center. Possibly hovering the icon would show what its for.
