<!DOCTYPE SONG SYSTEM "song.dtd">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
SYSTEM "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
A Document Type Declaration Information Item includes:
external DTD: An entity information item for the external DTD subset.
children: Only the comment and processing instruction information items in the internal DTD subset and external DTD subsets.
parent