HTML and CSS Reference
In-Depth Information
dubbed the “doctype switch.” When a browser sees a known standards-focused doctype
indicator, it switches into a standards compliant parse:
Strict DTD Present
However, if the
<!DOCTYPE>
statement is missing, references a very old version like 3.2,
or is unknown, the browser will enter into quirks mode. Browsers may provide an indication
of the rendering mode via an entry in page info:
DTD Missing
