HTML Checking for Large Sites

Rocket Validator automatically checks your pages on the W3C Validator.

Bad value “” for the attribute “xmlns” (only “” permitted here).

The only permitted value for the xmlns attribute is

The namespace declaration for an <svg> element is provided by the xmlns attribute like this:

<svg xmlns="">
  <!-- more tags here -->

Although using https in the URL looks like it’s going to be more secure, in fact this URL is not used to connect it to, only to declare the namespace.

Learn more:

* MDN: Namespaces crash course

Related W3C validator issues

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