The purpose is to say to developers if it's a new problem, or isn't. I can
think about six benefits:
1) It can save them the time for checking this.
2) It can be made better by task filer than by developer, because the first
knows better the problem.
3) It can save the time needed to them or other
If you don't have access to old mediawiki version (whether it is group2,
your own wiki or test3wiki suggested above),
and suspects there is a regression of something that was working in the
past,
it is useful to indicate it in the bug description, and the maintainer of
that feature can check it
