2.1.3.7 !DOCTYPE Declaration

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The following table lists examples of the most common <!DOCTYPE> declarations and how they influence which document mode is used.

<!DOCTYPE> declaration

Document Mode Impact

HTML 4.0 and higher

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3org/TR/html4/strict.dtd">

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3org/TR/html4/strict.dtd">

              

XHTML with or without a system identifier

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3org/TR/xhtml11/DTD/xhtml11.dtd">

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN" "http://www.w3org/TR/xhtml-basic/xhtml-basic10.dtd">

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3org/TR/xhtml1/DTD/xhtml1-strict.dtd">

Unknown

<!DOCTYPE html>

Standards mode or EdgeHTML in Microsoft Edge

XHTML Transitional or Frameset

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN">

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN">

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhmlt1-transitional.dtd">

HTML 4.0 or HTML 4.01 Transitional or Frameset with a system identifier

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3org/TR/html4/loose.dtd">

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3org/TR/html4/loose.dtd">

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3org/TR/1999/REC-html401-19991224/loose.dtd">

"Almost Standards" mode (standards mode in IE7)

HTML 4 and lower, or no DOCTYPE

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

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

None

Quirks Mode or Quirks Mode emulation in Microsoft Edge