By default our forums will show a "The topic or post you requested does not exist" for a post that is no longer in your forum ( or that was deleted ). last year I was getting annoyed with Google having caches of topics that no longer existed on my site. I thought that this little fix might help my problem and also redirect traffic to my custom 404 page. but not until recently I found a better benefit to this little modification.
Google sitemaps occasionally lists dead URL's ( or posts ) coming from my forum. but in order ...