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.
justinlittman
commented
6 years ago
The key
Source-URLis 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.