General-election battles for City Hall are hardly unheard of, of course.
Hardly unheard of for a novice to run away, but the farmer leaving too was troublesome.
It's not as though there's a pressing need to "put London on the map;" it's hardly unheard of as a tourist destination.
Although it is not common for editorial boards to include experts with little experience in journalism, it is hardly unheard of.
Escaping from captivity was unchivalric, and would carry consequences - but hardly unheard of.
Whether Cavendish's move was an act of generosity to his loyal lieutenant is unknown, though hardly unheard of in cycling.
Rowdy behavior is hardly unheard of.
Religious bodies' use of incentives and advertising to draw people to a particular congregation or geographical area is hardly unheard of.
Although it is unusual to be called to the Torah for the first time at such an advanced age, it is hardly unheard of.
An inch in an hour is ordinary, and six inches in a day is hardly unheard of.