HTML 3.2

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">

HTML 3.2 is well supported by most browsers in use. However, HTML 3.2 has limited support for style sheets and no support for HTML 4 features such as frames and internationalization.

HTML 2.0

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">

HTML 2.0 is widely supported by browsers but lacks support for tables, frames, and internationalization, as well as many commonly used presentation elements and attributes.

Syntax

• <!DOCTYPE [version-specific string]>

Remarks

The <!DOCTYPE> declaration is not an HTML tag. It is used for specifying which version of HTML the document is using. This is referred to as the document type declaration (DTD).

The <!DOCTYPE> declaration is NOT case sensitive. To check if the HTML of your Web pages is valid, go to W3C's validation service (opens new window).

• Some old versions of IE don't support some HTML tags unless a proper doctype is available.
• It's vital that a doctype is declared as to make sure the browser doesn't use quirks mode. More info on MDN. (opens new window)