Document Type Definition
<!DOCTYPE> (Document Type Definition)
This SGML construct specifies the document type definition corresponding to the document. There are no attributes or events associated with this element.
Standard Syntax
<!DOCTYPE "DTD IDENTIFIER">
Examples
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 TRANSITIONAL//EN">
<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 TRANSITIONAL//EN">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www
.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "xhtml11.dtd">
<!DOCTYPE html>
Compatibility
| Standards | Browser |
|---|---|
| HTML 2, 3.2, 4, 4.01, 5 | Firefox 1+, Internet Explorer 2+, |
| XHTML 1.0, 1.1, Basic | Netscape 1+, Opera 4+, Safari 1+ |
Notes
- The <!DOCTYPE> statement should be used as the first line of all documents.
- Validation programs might use this construct when determining the correctness of an HTML document.
- While HTML5 does not follow the SGML/XML concept of validation, the <!DOCTYPE> is still used. HTML5 does however provide for syntax checking currently dubbed conformance checking. Note though that conformance checking does not rely on XML/SGML grammar.
- While HTML5 does not follow the SGML/XML concept of validation, the Modern browsers may determine what rendering mode to use depending on the <!DOCTYPE> statement. This is dubbed the doctype switch. An incorrect <!DOCTYPE> that does not correspond to appropriate markup usage may result in inaccurate display