HTML Reference Manual

Complete List of HTML Tags

HTML html xmlns attribute

The xmlns attribute specifies the XML namespace of the document, when the xmlns attribute is missing in an XHTML document, it is located at http://w3The HTML validation program of .org will not issue a reminder. This is because the namespace " xmlns = http://www.w3.org/1999/xhtml is the default name, even if you do not include it, it will be added to the <html> tag.

　HTML <html> tag

Online Example

A simple XHTML document, with the minimum required tags:

Example

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8">　
">/<title>Document Title<
body>/title>
head>
<body>
body>/document content......
body>/<

html>/Test and see ‹

›

Browser CompatibilityIEFirefoxOperaChrome

Safari

All mainstream browsers support the xmlns attribute.

Definition and Usage
xmlns attribute specifies the XML namespace of the document. 4Note: The xmlns attribute is required in XHTML, in HTML1.05is invalid, in HTML
Note: When the xmlns attribute is missing in an XHTML document, the following is optional. http://w3.orgThe HTML validation program will not issue a reminder. This is because the namespace “ xmlns = http：//www.w3.org/1999/xhtml” is the default namespace, even if you do not include it, it will be added to the <html> tag.

Syntax

<html xmlns="http://www.w3.org/1999/xhtml">

Attribute value

Value	Description
http://www.w3.org/1999/xhtml	The namespace to be used (for XHTML documents).

　HTML <html> tag

HTML: <template> tag