The list format used by tdom represents a node in a document by a list in one of the forms
(possibly there could be more), where the first two are the most important. The children is again a list (possibly empty) of such list representations of nodes. The attribute-dict is a dictionary mapping attribute names to their values, neither of which have any quoting of special characters. Similarly, the text is character data between tags, without any XML-quoting. #pi nodes are for XML processing instructions.
Appears similar to the tdom list format, except that there are two extra items in each node:
See can2svg, particularly the definition of can2svg::MakeXML.