2. Sarcastic: A response which satirically downplays something important. Any usage which is used to satirically highlight a use given in definition 1.
Notes: This can be used either as a "subject" (grammatically) or as a response to another's comment.
Johnny: OMG, I lost my receipt from the gas station the other day!
Jane: Minor details, don't sweat it.
Johnny: I totally blew my math final!
Jane: Minor details. :P