C1
Field 53a may only be present if field 34P is used (Error code(s): C20).
C2
Field 31C may only be present in the case of an American style option (ie, subfield 3 of field 23 contains 'A') (Error code(s): C79).
C3
The currency in the amount fields 32B and 34a must be the same (Error code(s): C02).