Champs
BHRC = Mintex MSA British Historic Rally Championship    
WELSHNAT = Pirelli MSA Welsh Stage Rally Championship    
WELSHHIST = Brian Dennis Motorsport Welsh Historic Rally Championship    
HRCR = West Wales Rally Spares HRCR Stage Masters Challenge    
FMP = FMP Rally Championship    

Class
B1 = Amalgamated with B2 (Nat A. Historic event)    
B2 = Cat 1. 1001cc - 1300cc. Reg'd on or before 31/12/67 (Nat.A Historic event)    
B3 = Cat 1. 1301cc - 1600cc. excl. Twin-cam. Reg'd or before 31/12/67 (Nat.A Historic event)    
B4 = Cat 1. 1601cc - 2000cc. incl. Twin-cam. excl. 911, Reg'd or before 31/12/67 (Nat.A Historic event)    
B5 = Cat 1. Over 2000cc. incl. all Porsche 911s. Reg'd on or before 31/12/67 (Nat.A Historic event)    
C1 = Cat 2. Amalgamated with C2 (Nat.A Historic event)    
C2 = Cat 2. Up to 1600cc. incl. 2-valve-Twin-cam. Reg'd between 1/1/68 and 31/12/74 (Nat.A Historic event)    
C3 = Cat 2. 1601cc - 2000cc. Reg'd between 1/1/68 and 31/12/74 (Nat.A Historic event)    
C4 = Cat 2. Amalgamated with C5 (Nat.A Historic event)    
C5 = Cat 2. Over 2000cc. incl. all Twin-cam and multi-valve. Reg'd between 1/1/68 and 31/12/74 (Nat.A Historic event)    
D1 = Cat 3. Amalgamated with D2 (Nat.A Historic event)    
D2 = Cat 3. Up to 1600cc. incl. 2-valve-Twin-cam. Reg'd between 1/1/75 and 31/12/81 (Nat.A Historic event)    
D3 = Cat 3. 1601cc - 2000cc. Reg'd between 1/1/75 and 31/12/81 (Nat.A Historic event)    
D4 = Cat 3. Over 2000cc. incl. all Twin-cam and multi-valve. Reg'd between 1/1/75 and 31/12/81 (Nat.A Historic event)    
D5 = Cat 3. All other Twin-cam multi-valve. Reg'd between 1/1/75 and 31/12/81 (Nat.A Historic event)    
E1 = Cat 4a. Up to 1600cc. Reg'd between 1/1/82 and 31/12/85 (Nat.A Historic event)    
E2 = Cat 4a. 1601cc and over. Reg'd between 1/1/82 and 31/12/85 (Nat.A Historic event)    
F1 = Cat 4b. Up to 1600cc. Reg'd between 1/1/86 and 31/12/90 (Nat.A Historic event)    
F2 = Cat 4b. 1601cc and over. Reg'd between 1/1/86 and 31/12/90 (Nat.A Historic event)    
G1 = Cat K. Up to 1600cc. FIA Appendix K Reg'd on or before 31/12/85    
G2 = Cat K. 1601cc and over. FIA Appendix K Reg'd on or before 31/12/85    
BB1 = Cat 1. Up to 1600cc excl. Twin-cam. Reg'd on or before 31/12/67 (Nat.B Historic event)    
BB2 = Cat 1. 1601cc and over incl. Twin-cam. Reg'd on or before 31/12/67 (Nat.B Historic event)    
BC1 = Cat 2. Up to 1600cc excl. Twin-cam. Reg'd between 01/01/68 and 31/12/74 (Nat.B Historic event)    
BC2 = Cat 2. 1601cc and over incl. 2-valve-Twin-cam. Reg'd between 01/01/68 and 31/12/74 (Nat.B Historic event)    
BD1 = Cat 3. Up to 1600cc excl. Twin-cam. Reg'd between 01/01/75 and 31/12/81 (Nat.B Historic event)    
BD2 = Cat 3. 1601cc and over incl. 2-valve-Twin-cam. Reg'd between 01/01/75 and 31/12/81 (Nat.B Historic event)    
BE1 = Cat 4a. Up to 1600cc. Reg'd between 01/01/82 and 31/12/85 (Nat.B Historic event)    
BE2 = Cat 4a. 1601cc and over. Reg'd between 01/01/82 and 31/12/85 (Nat.B Historic event)    
BF1 = Cat 4b. Up to 1600cc. Reg'd between 01/01/86 and 31/12/90 (Nat.B Historic event)    
BF2 = Cat 4b. 1601cc and over. Reg'd between 01/01/86 and 31/12/90 (Nat.B Historic event)    
BG1 = Cat K. Up to 1600cc. Appendix K Reg'd on or before 31/12/85 (Nat.B Historic event)    
BG2 = Cat K. 1601cc and over. Appendix K Reg'd on or before 31/12/85 (Nat.B Historic event)    
M1 = Up to and including 1400cc (Nat.B Modern event)    
M2 = 1401cc to and including 1600cc. (Nat.B Modern event)    
M3 = 1601cc - including 2000cc. (Nat.B Modern event)    
M4 = Over 2000cc. (Nat.B Modern event)    
M5 = All 4-wheel drive other than M6 (Nat.B Modern event)    
M6 = All Group N 4-wheel drive (Nat.B Modern event)