[jgraham]

Work with attributes whose name doesn't match the XML Name production.

That can be a real concern in some cases (it came up recently in the context of "how do I move all the attributes on node A to node B, given that node A's attributes can be anything that can be created by the HTML parser?" c.f. https://software.hixie.ch/utilities/js/live-dom-viewer/?save... )

[jaffathecake]

Hah, good insight! I didn't realise you could move attributes either. I tried, but seems (unlike nodes) you need to remove them before adding them.