There is no valid attribute named recursive in HTML. Check the HTML atributes reference here: https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes
It's complete list of HTML attributes with descriptions.
All I was able to find regarding recursive="true" was a Umbraco CMS forums, where they mention this, but it's different context - not being used directly in HTML.
> If recursive is on, it will look at the parent for existing meta info and if the parent doesn't have anything, it looks in the grandparent, and up, all the way to the highest node in the tree.
That's about it. Can you tell us where did you see that?
<title recursive="true"></title> <link rel="icon" type="image/png" href=""/> <meta name="description" content=" " recursive="true"/> <meta name="keywords" content="" recursive="true"/>