Thank you for the heads up, that seems to be an accidental regression. This section was updated a while back, and the correct version of that section is deployed in the previous version of the docs. Until we’re able to resolve the issue, you can reference the version at the link I sent; I don’t believe there have been any changes to the format since then.
The example does not include XML headers. Exported experiments don’t either.
The last paragraph specifies the XML headers still.
Are they still needed for the headless runner?
Good question, and good catch! You do need the standard XML header for the headless runner, although you no longer need the DOCTYPE header. It seems that the lack of a header in exported experiments was a bug, which is now fixed.