TUPLE: document parse-errors skip-leading-newline? pending-table-characters
template-insertion-modes active-formatting-elements
quirks-mode? limited-quirks-mode? iframe-srcdoc? scripting?
frameset-ok? fostering-parent? tree tree-doctype
head-element-pointer form-element-pointer
parser-cannot-change-mode-flag insertion-mode
original-insertion-mode last node context doctype tag
end-tag tag-name end-tag-name attribute-name attribute-value
temporary-buffer comment-token processing-instruction-token
open-elements return-state
;