Optional Readonlyextensionsthe file extensions this format is usually written with, lowercase and dotted. Documentation and tooling only: the loader never decides on a name.
Readonlynamehow this format is named in diagnostics and in the tools; unique among registered formats
Optional Readonlyprioritywhich format wins when more than one claims a document. Higher is stronger; the default is 0. NodeSet2 XML registers at -100 because it is the fallback: it claims anything no other format recognised, which is the behaviour the loader has always had.
what the document depends on, read without parsing its body
the document's records, in document order
Optionaloptions: NodeSetLoaderOptionswhether this format claims the document that begins like this
a serialisation the loader can read