Why does Safari sometimes bookmark a different URL? I noticed this in Wikipedia redirect pages using iOS 12.1.1

For example, if you open this URL


https://en.wikipedia.org/w/index.php?title=UK&amp;redirect=no


Then use “Add bookmark” or “Add to Favorites”, iOS instead bookmarks this URL:


https://en.wikipedia.org/wiki/UK


(Wikipedia then automatically redirects it to https://en.wikipedia.org/wiki/United_Kingdom .)

“Add to Reading List” seemingly uses this amended URL too, while “Add to Home Screen” uses the unchanged https://en.wikipedia.org/w/index.php?title=UK&amp;redirect=no .

Is there a technical explanation for how/why this happens?
Then use “Add bookmark” or “Add to Favorites”, iOS instead bookmarks this URL:
  https://en.wikipedia.org/wiki/UK


The rest of the title is telling it not to redirect as it is a redirect page as is removed.


  (Wikipedia then automatically redirects it to https://en.wikipedia.org/wiki/United_Kingdom .)


The page is a redirect page so it redirects it unless you put &amp;redirect=no at the end of the title


  “Add to Reading List” seemingly uses this amended URL too, while “Add to Home Screen” uses the unchanged


Add to reading list is the same explanation while add to home screen just copies the link.