Any involving the move A Ber-Sil. The following named variants exist:
Also known as the Frederich Opening, this opening was named by John Mark. France should be pleased and more inclined to move against England, and Silesia can guard Munich against A Bur-Mun just as well as Kiel can. It also gives protection against A War-Sil.
Again, Munich is the "swing." Here Germany goes after Russia and Austria, or Austria alone. Both armies threaten Galicia as well as two supply centers. Against Austria alone, A Boh-Vie, A Sil-Gal will hurt.