Caro-Kann DDG

1. e4 c6 2. d4 d5 3. c4 is called the Caro-Kann Diemer-Duhm Gambit. Its ECO code is B12/01. If Black will play e6 before Bf5 or Bg4, the game transposes to the French Defence DDG.
B

3... e6

3... e6 transposes to a variation of the French Defence DDG Declined.

3... dxe4

3... dxe4 4. Nc3 Nf6 5. f3 exf3 (5... Bf5!?) 6. Nxf3 Bg4 7. Be3 e6