In HTML 4.01, the DOCTYPE It is a statement to declare the type of the document. The web value rate of dcnm.ir is 191,316 USD. Windows Dev Center Home ; UWP apps; Get started; Design; Develop; Publish; Resources . 1. doctype. Its main purpose is to prevent the browser from entering 'Quirks Mode' while rendering the document. An example HTML5 document If specified, it has to be at the beginning of the HTML document just after the Byte-Order-Mark (BOM) if any. To set the doctype in HTML5, add this to the top of your html code: How to add required attribute to an input box jquery. This happens because the 4.01 version of HTML is based on Standard Generalized Markup Language(SGML). Therefore, it must be declared in the first line of an HTML code. Browser support. HTML document structure. Its sole purpose is to prevent a browser from switching into so-called "quirks mode" when rendering a document; that is, the "" doctype ensures that the browser makes a best-effort attempt at following the relevant specifications, rather than using a different rendering mode that is incompatible with some specifications. The latest version of HTML is HTML5, and the doctype for that version is simply . From W3Schools.com: otherwise, browser will guess and will go to quirks mode.