Not quite. If you're using VSRE, the information contained in those headers is already implicit. I can't think of an example off the top of my head, but I'm sure there are protocols where you don't need to send loquacious headers or equivalent with every response. "VSRE" says, "go ahead and assume I know what the headers would be and skip them". If you're not expecting headers, it's not a problem if they're missing.