Allen-Bradley 1779-KFMR User Manual page 166

If the STS field in the reply header has a value other than 00, that
indicates an error reply which has no message fields for the application
layer.
Error Reply Format:
Delete Remote Command
Use this command to delete a remote command stored at a remote
programmable controller station. With the RCID field, specify the remote
command to be deleted.
Command Format:
The reply has no message fields for the application layer. However, the
STS field in the header indicates a successful transaction (00) or an error
code.
Reply Format:
Chapter 10