[Value] The internal subset. [Node Type] 
DocumentType
A t t r i b u t e
C D A T A
C o m m e n t
D o c u m e n t T y p e
P r o c e s s i n g I n s t r u c t i o n
S i g n i f i c a n t W h i t e s p a c e
T e x t
W h i t e s p a c e
X m l D e c l a r a t i o n