Link to fragment - Help please Options

[eagertoknow]

Not sure if this is the right place to ask this, but here goes:
I want to create a link to a specific text fragment of a web page that I highlight, so the user won't have to scroll through a potentially lengthy document and search for the fragment I want him to read. Instead, the page should scroll directly to the fragment.
I know there are various browser extensions like "Link to Fragment" and others that allegedly do the job, but they don't work for me (using Brave). They all rely on defining the fragment using the first and the last few words embedded in the generated link (using :~: after the hash sign).
However, someone knows a better way, and it works every time.
In one of his articles, he links to this, highlighted in the article: "the U.S. economy rose 4.24 times, the EU rose 3.90 times, and China rose 21.83 times, during that period from 1980 till 2022".
And here is the link he generated:

CODE

https://archive.is/rJfIP#selection-1183.224-1183.300

Going there will scroll the page to the fragment and highlight it.
The part up until the hash mark is just the address of the entire page he archived using archive.is.
The interesting part is what follows, starting with #selection.
It obviously identifies the start and end of the fragment.
I have never seen nor do I understand this syntax, and I have dug up all I could about fragments and linking to them.
The author seems to use direct coordinates without the need to embed text in the generated link. He didn't tell me how he does it, except "I select the fragment, move the cursor to the address bar, and copy the link from there." I don't know what browser he is using.
To put it differently: Why does the above link work, and what do the parameters mean?
Any help greatly appreciated.