What doctype declarations do you know

Browser vendors would build new features in whatever way they wanted. There was little concern for competing browsers. The result was that web developers had to choose a browser to develop their sites for. This meant that sites would not render well in unsupported browsers. This situation could not continue. All browser vendors and web developers should adhere to these standards. This would ensure that websites would render well across browsers.

The changes required by the standards were quite different from some existing practices. Adhering to them would break existing non standards compliant websites. To handle this problem, vendors began programming rendering modes in to their browsers.

Web developers would need to add a doctype declaration to the top of an HTML document. What happens if we do not use the Doctype declaration in an HTML document and try to render it on a browser? Well, the browser will read it as invalid since this goes against standards-compliant mode. However, the browser would fall back to its former version.

This means that the browser figures out that there could be compatibility, and parses the HTML or other markup language document in question. For instance, Microsoft Edge would probably revert to a previous version similar to the old Internet Explorer and try to parse and display the CSS files that way.

The same thing would happen if it were on Firefox or any other modern browser. But then the displayed page may not look up to date, and one would be able to tell there is something wrong.

It can also result in different user experiences since each visitor uses a different operating system and a different browser. Since HTML 4. For the browsers to comply and render information as it should, the document type definition must be given so that it stipulates the rules for SGML.

Also, all HTML 4. In turn, the public identifiers of these DTDs are constant and are as follows:. In the HTML 5 version, the Doctype as seen earlier is much shorter, since there is no use of document type definition that includes referencing a complete URL.

Your email address will not be published. This HTML doctype declaration also contains all elements and attributes, but no presentational and deprecated elements. However, it must be written in strict XML :. Learn to use HTML tag here! Code has been added to clipboard! Reading time 3 min. Contents 1. HTML 4. XHTML 1. Example Copy.