C1
In each occurrence of subsequence C1a, the presence of subsequence C1a1 depends on the value of field :17B::SECU//<Flag> as follows (Error code(s): E66):
C2
In each occurrence of subsequence C1a, the presence of field :98a::SETT depends on the value of field :17B::COLL as follows (Error code(s): E72):
C3
In each occurrence of subsequence C1a1, the presence of field :70C::RATS depends on the presence of field :94B::RATS as follows (Error code(s): E60):
C4
If Sequence A field :22a::COLA// is other than SLEB and sequence C is present then, in every occurrence of subsequence C1, field :19A::TRAA must be present. (Error code(s): E65).
If the message is a cancellation, ie, Function of the Message (field 23G) is CANC, then subsequence A2 (Linkages) must be present at least once in the message, and in one and only in one occurrence of A2, field :20C::PREV must be present; consequently, in all other occurrences of A2, field :20C::PREV is not allowed (Error code(s): E08).