ORIGINAL: Shannon V. OKeets
She went boom!
Scharnhorst and Gneisenau were never classified or labeled as pocket- battleships.
The Scharnhorst class were battleships with heavy armour (max 13 3/4 inch belt - Bismarck class had max 12 1/2 inch) but only "medium" armament (9x280 mm = 11 inch), because the 280 mm turret was readily available from the pocket battleship class (Deutschland/Lützow, Admiral Scheer, Admiral Graf Spee). Development of the planned 380 mm (15 inch) turret for the Scharnhorst class, which was allowed for by the Anglo-German Naval Agreement of 1935, would have taken some years, so it was decided for sake of Hitler's power-politics, to complete the ships quickly with the lighter armament and to re-arm them later.
As far as I rememeber the term "pocket battleship" was invented in Anglo-American newspapers for the Deutschland-class "armoured ships" ("Panzerschiffe"), as the Reichsmarine labeled them.
The particularity of the construction of the Deutschland class was, that it found a way between international armament restrictions (for Germany the Treaty of Versailles forebade to built larger warships than 10.000 tons, for the USA, GB, France and Japan the Washington treaty made the 10.000 tons "Washington-cruisers" mandatory) and the German naval strategy of cruiser warfare ("Kreuzerkrieg"):
The Reichmarine built a class of ,eehr, 11.700 tons ships, which were more heavily armed and armoured than the Washington cruisers, but faster than enemy battleships.
To counter the threat of the pocket battleships the tactical and strategic concentration of multiple cruisers worked quite well, as the Battle of the Rio de la Plata showed.