Chess is a scientific game and its literature ought to be placed on the basis of the strictest truthfulness, which is the foundation of all scientific research. — W._Steinitz

C00-C99

C00-C19		French
C20		King's Pawn
C21-C22		Center Game
C23-C24		Bishop's Opening
C25-C28		Vienna
C29		Vienna Gambit
C30		King's Gambit Declined
C31-C32		Falkbeer Counter-Gambit
C33-C39		King's Gambit Accepted
C40		Irregular King's Knight
C41		Philidor
C42-C43		Petrov
C44		King's Knight/Ponziani/Scotch
C45		Scotch
C46		Three Knights
C47-C49		Four Knights
C50		Italian
C51-C52		Evans Gambit
C53-C54		Giuoco Piano
C55-C59		Two Knights
C60-C99		Spanish