HTML 4x01 strict declaration
<!DOCTYPE> declaration must be the very first thing in your HTML document, before the <html> tag.
This declares the document to be HTML 4.01 Strict. HTML 4.01 Strict is a trimmed down version of HTML 4.01 that emphasizes structure over presentation.
This DTD contains all HTML elements and attributes, but does NOT INCLUDE presentational or deprecated elements (like font and center).