The name of the entry is a reference to a local joke name for the city of Londonderry/Derry. That thing between the words "Londonderry" and "Derry" is called a "stroke" in some versions of English. An American would call it a "slash", which could have some pretty strange unintended implications (William of Orange/James II Foe Yay?). The city is officially called Londonderry, but has a City Council that calls it "Derry". An attempt to compromise is "The Maiden City", since it wasn't breached in a 1689 siege. Fiction set in Northern Ireland that doesn't involve The Troubles: