The `<link>` element is an empty element, it contains attributes only. In HTML5 the `<link>` tag has no end tag. In XHTML the `<link>` tag must be properly closed.
In XHTML, the <input> tag must be properly closed, like this `<input />`. In HTML5 the `<input>` tag has no ending slash. https://www.w3schools.com/tags/tag_input.asp
Barnabus