Inclusion of the Number of Failed Sub-operations is conditional based upon the status in the C-MOVE response. The Number of Failed sub-operations specifies the number of C-STORE sub-operations generated by the requested transfer which have Failed.
A C-MOVE response with a status of:
Pending shall contain the Number of Failed Sub-operations Attribute
Canceled, Warning, Failure, or Success may contain the Number of Failed Sub-operations Attribute