ECO CHESS CODES C0-C1 - French Defense
C00 - French Defense 
1. e4 e6

C01 - French Defense, Exchange Variation 
1. e4 e6  
2. d4 d5   
3. ed5 ed5

C02 - French Defence, Advanced Variation
1. e4 e6   
2. d4 d5   
3. e5

C03 - French Defence, Tarrasch Variation
1. e4 e6  
2. d4 d5  
3. Nd2

C04 - French Defence, Tarrasch Variation/Guimard system
1. e4 e6   
2. d4 d5   
3. Nd2 Nc6  
4. Ngf3 Nf6

C05 - French Defence, Tarrasch Variation
1. e4 e6   
2. d4 d5   
3. Nd2 Nf6

C06 
1. e4 e6   
2. d4 d5   
3. Nd2 Nf6   
4. e5 Nfd7   
5. Bd3 c5
6. c3 Nc6   
7. Ne2 cd4   
8. cd4

C07
1. e4 e6   
2. d4 d5   
3. Nd2 c5

C08
1. e4 e6  
2. d4 d5   
3. Nd2 c5   
4. ed5 ed5

C09
1. e4 e6   
2. d4 d5   
3. Nd2 c5   
4. ed5 ed5   
5. Ngf3 Nc6

C10 French Defense
1. e4 e6   
2. d4 d5  
3. Nc3

C11 French Defence, Classical Variation
1. e4 e6   
2. d4 d5   
3. Nc3 Nf6

C12 French Defence, MacCutcheon Variation
1. e4 e6  
2. d4 d5   
3. Nc3 Nf6   
4. Bg5 Bb4

C13 French Defence, Classical Variation
1. e4 e6   
2. d4 d5  
3. Nc3 Nf6   
4. Bg5 Be7

C14 
1. e4 e6   
2. d4 d5   
3. Nc3 Nf6   
4. Bg5 Be7   
5. e5 Nfd7
6. Be7 Qe7

C15 Winkelmann-Reimer Gambit 

1. e4 e6   
2. d4 d5   
3. Nc3 Bb4

C16 
1. e4 e6   
2. d4 d5   
3. Nc3 Bb4   
4. e5

C17 
1. e4 e6  
2. d4 d5   
3. Nc3 Bb4   
4. e5 c5

C18 
1. e4 e6   
2. d4 d5   
3. Nc3 Bb4   
4. e5 c5   
5. a3 Bc3 
6. bc3

C19
1. e4 e6   
2. d4 d5   
3. Nc3 Bb4   
4. e5 c5   
5. a3 Bc3   
6. bc3 Ne7

ECO Chess Codes