Did an editorial pass over the document, rewriting most of the prose slightly.
Caught a place or two that was still referring to tags for object keys.
Sole non-editorial change was adding the final ambiguous case - a completely empty node. These are required to have an `(array)` or `(object)` tag to be valid.
`-` is slightly easier to type than `_` (no Shift, at least on american keyboards), and it's consistent with the "dummy" node name I'm planning to use for text nodes in XML-in-KDL.
(`_` is a valid XML element name, so I can't use that in XiK.)
Lars Willighagen
Tab Atkins Jr
Bram Gotink