Name is the element name, and Model is the content model as a string. The Elname parameter is the name of the element with which the attribute is being associated. The Attname parameter is the name of the attribute. Type is the attribute type, given as a string. If Fixed is true, then this is a fixed attribute.
Name is the document type name.
Internal is the internal subset, given as a string. If there was no internal subset, it will be undefined. Internal will contain all whitespace, comments, processing instructions, and declarations seen in the internal subset. However, comments and processing instructions will not appear if they've been processed by their respective handlers. This handler is called for xml declarations.