The attribute used on the `<iframe>` element is obsolete.

# How do I fix this ?

A simple fix is to replace the attribute using CSS:

`<iframe frameborder="0" … />`

becomes

`<iframe style="border:0;" … />`

# Resources

* [iframe fixes](http://help.simplytestable.com/errors/html-validation/the-x-attribute-on-the-y-element-is-obsolete-use-css-instead/the-frameborder-attribute-on-the-iframe-element-is-obsolete-use-css-instead/)
* [MDN iframe](https://developer.mozilla.org/en/docs/Web/HTML/Element/iframe#Notes)