Searching on Google I found the question "Java : File.toURI().toURL() on Windows file" with an accepted answer that contains the unfortunate misunderstanding that RFC3986 forbids "file" URIs with an empty host component (e.g. that file:///path is an illegal URI):
Since file URIs have no authority segment, they're forbidden from starting with //.
I think users expect that the information in an accepted, up-voted answer on Stack Overflow is true. If accepted, up-voted answers, which will likely be ranked high on Google and considered authoritative by many, contain false information it will misinform people and risk undermining the credibility of Stack Overflow.
I thought that fixing this information bug would improve the quality of information found in the internet ever so slightly, perhaps preventing future bugs from being introduced due to a wrong understanding of URIs, so I tried to fix it, but the fix was rejected. Maybe because it changes the meaning of the accepted answer.
So I guess I went about it the wrong way. What is the correct process for fixing wrong information in an accepted answer?