I'm reading Rec. ITU-R M.1172 and its precise definition of Q-code QSD is "Are my signals mutilated? Your signals are mutilated." 

From what I've seen, QSD is usually used to check if keying is defective, but this is the first time I've seen word "mutilated" used to describe defectiveness. 

So my question is: Is there any deeper meaning to mutilated other than defective here?