In HTML, ID attributes may contain any character

From the [HTML specification](https://html.spec.whatwg.org/multipage/dom.html#the-id-attribute):

> When specified on HTML elements, the id attribute value must be unique amongst all the IDs in the element's tree and must contain at least one character. The value must not contain any ASCII whitespace.
>
> [...]
>
> There are no other restrictions on what form an ID can take; in particular, IDs can consist of just digits, start with a digit, start with an underscore, consist of just punctuation, etc.

This means that URL fragments are encoded. Pipeline currently does not take this into account when matching hyperlinks with elements.