I        This condition is triggered when a connected client sends a HEAD request.


A HEAD request is meant to be treated like a GET request, so you send the exact same response, but without the content. For example, if it's a 4MB file, you send the header including content-length being 4MB, but don't actually attach the 4MB file.


Web Query Object can use HEAD requests.

The Get object does not use HEAD, and Download object only uses it via the "get content size from URL" expression.