The Mapping Request Control Block (MRCB) exception codes are used to indicate input errors from a terminal. Data entered at a terminal that conflicts with the field definition for the mapping field in which it is entered is not returned in the buffer area. Instead, the name of the mapping field, followed by an exception code, is listed in the feedback area.

Error Code	Field Types
ND	All
NN	Z
NN	P,H,F
OF	All
UF	P,H,F
MR	All