I have been reviewing a lot of older posts (~10 years old) and there are quite a few with links that are either dead or links that point to sites that no longer contain the relevant information that the link was originally referring to.
In one case, I found a comparable site that contained the result the dead link cited and replaced the link in an edit. But in a lot of cases where someone is not citing a specific result, this is sometimes not possible.
Should the 10-year-old question be edited to remove the dead link? Is there any policy on the process to take when deciding on what to do with a dead or stale link? Surprisingly, I couldn't find an existing discussion on this. There is a small sub-discussion on this topic in this question:
What to do with links to arXiv front end?
As an example of what I encountered, this posting:
has a link to a pdf document at:
and while the link is not dead (it still goes to the ICM Math Union website) it does not find this pdf file it tried to cite. The question could potentially have this extra tidbit of information removed without affecting the message quality of the question.
Should there be a policy? Could I propose an edit that I feel makes the most sense? I wouldn't know if my decision is breaking any rules (written or unwritten) around editing.