Definitions for "DOCTYPE"
Keywords:  dtd, syntax, declares, tells, tag
A directive, found at the top of an HTML document, that indicate the document type used in the markup of the document itself. A DTD (Document Type Definition) describes the markup that can be used in a document that uses the DTD. The DOCTYPE is used when validating a document, and is used by some browsers to determine which rendering mode to use in the display of the document (see DOCTYPE switching).
a declaration that works as a top-level tag-like reference known as a Public Identifier
a Document Type definition, which tells the browser what version of HTML you have coded the page in
Keywords:  switch, page
a switch on a page