[Accessibility ]Use a public text identifier in a DOCTYPE statement in Update page

[atreyeemukhopadhyay]

The !DOCTYPE declaration is a top-level tag-like reference known as a Public Text Identifier. It appears at the very beginning of an HTML document in order to identify the content of the document as conforming to a particular HTML DTD specification.

The quoted segment within a !DOCTYPE declaration is called a Formal Public Identifier (FPI.) Every distinct DTD variation will have its own unique FPI string.

DOCTYPE in a document served as text/html determines a layout mode, such as "quirks mode" or "standards mode". The document type declaration names the document type definition (DTD) in use for the document