xmlns:xsi

XML Schema Namespace Declaration

This is not an attribute, but a namespace pseudo-attribute. The value provides a prefix to use for the MathML @xsi:schemaLocation attribute. All namespace prefixes must be associated with a URL, and the prefix “xsi” has been set to the URL for the World Wide Web Consortium (W3C) XML Schema.

Attribute Values

In Element

<article>
ValueMeaning
http://www.w3.org/2001/XMLSchema-instanceThe prefix “xsi” has been set to the URL of the W3C XML Schema.
Restriction: Restriction: This attribute value may not be changed.