As described in the Here is How This will Work section, the implementation is humble. It either scrolls the page to the first instance to the string in the frag

As described in the Here is How This will Work section, the implementation is humble. It either scrolls the page to the first instance to the string in the fragment or it scrolls and highlights text included and between two comma-separated strings (commas in the strings themselves would need to be url encoded). If you wanted to scroll to the nth instance of a string, you've have to use the latter format and include more text, making it unique or at least the first instance. Yes, it would fail if the target text no longer exists in the page but link rot is already commonplace. It would be important for it to ignore DOM elements, it can't fail because the target text crosses two paragraphs or a span.