If I have a Confluence page at `https://confluence.americas.mysite.com/display/SE/Potato+Salad` and someone changes the page title to "Macaroni Salad" any previous bookmark of that page is broken. I can use the "sharing" url, but to bookmark that page I have to go into my bookmark manager (in Chrome at least) and manually edit the bookmark. If I just click the bookmark (star) button in Chrome the bookmark will be broken by anyone who changes the page title. 

 

I am aware that confluence will show the user a page with the most likely new page for that url. This seems more fragile than using a canonical url. 

 
SO does this right:

https://stackoverflow.com/questions/66960510/expo-barcode-scanner-is-deleting-null-characters

and

https://stackoverflow.com/questions/66960510/ZZZZZZZZZZZZZZZZZexpo-barcode-scanner-is-deleting-null-characters

go to the same place because the latter part of the url is only there for SEO reasons.