ECO volume C: Open games and the French Defense

ECO C91

3 named openings and variations are classified as C91. ECO (Encyclopaedia of Chess Openings) codes group openings from A00 to E99 by their opening moves.

Ruy Lopez: Closed, Bogoljubow VariationC911. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. d4 Bg4
Ruy Lopez: Closed, Yates VariationC911. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. d4
Ruy Lopez: Closed, Yates Variation, Short AttackC911. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. d4 Bg4 10. a4