HTML Guide for namespace

The only permitted value for the xmlns:link attribute is http://www.w3.org/1999/xlink.

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.

The only permitted value for the xmlns attribute is http://www.w3.org/2000/svg.

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

<svg xmlns="http://www.w3.org/2000/svg">
  <!-- more tags here -->
</svg>

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.