C1
In sequence A, if field :20C::CLCI is not present, then field :20C::TRCI is mandatory, otherwise field :20C::TRCI is optional (Error code(s): E64).
C2
In sequence A, if field :20C::SCTR is not present, then field :20C::RCTR is mandatory, otherwise field :20C::RCTR is optional (Error code(s): E68).
C3
In sequence A, if the value of field :23G:<Function> subfield 1 is REPL, then sequence B is not allowed, otherwise it is mandatory (Error code(s): E08).
C4
If sequence A field :22a::COLA// is other than SLEB and sequence B is present, then field :19A::TRAA must be present. (Error code(s): E65).
(*) if the Data Source Scheme is present in field :22F::COLA// then the conditional rule does not apply.