The key Source-URL is not defined anywhere else. It's confusing to use it in this example, even if "other arbitrary metadata elements MAY also be present."
If we want to show "custom" keys then that should be a different example - we should not violate our own MAY in an unrelated example.
The key
Source-URL
is not defined anywhere else. It's confusing to use it in this example, even if "other arbitrary metadata elements MAY also be present."If we want to show "custom" keys then that should be a different example - we should not violate our own MAY in an unrelated example.