The following list lists those codes that were used on BR cross-referred to the comparable code used by the LMS , with the exception that the letter `` S '' ( '' `` Second '' , later `` Standard '' ) is used where until 1956 the letter `` T '' ( `` Third '' ) was used .
The following list lists those codes that were actually used on British Railways , cross-referred to the comparable code used by the LMS , with the exception that the letter `` S '' ( '' `` Second '' , later `` Standard '' ) is used where until 1956 the letter `` T '' ( `` Third '' ) is used .