ECO volume D: Closed and semi-closed games

ECO D68

One named opening is classified as D68. ECO (Encyclopaedia of Chess Openings) codes group openings from A00 to E99 by their opening moves.

Queen's Gambit Declined: Orthodox Defense, Classical VariationD681. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. e3 O-O 6. Nf3 Nbd7 7. Rc1 c6 8. Bd3 dxc4 9. Bxc4 Nd5 10. Bxe7 Qxe7 11. O-O Nxc3 12. Rxc3 e5