I don't recall, but you could try this script (as your 404 page, or put the code in it at least) and see if you see anything that seems to fit the bill: 
#!/usr/bin/perl

print "Content-type: text/html\n\n";
foreach $key (keys %ENV)
{
  print "$key: $ENV{$key}<br>";
}

[download]
Update: Browsing the apache docs a little, it would seem as if there are some new environment variables created, prefixed with REDIRECT_ that is probably what you are looking for. More info here. If you are not using apache, my bet is that the server has the same variables, or something similar accessible anyways. Look at the appropriate docs. :)
You have moved into a dark place.
It is pitch black. You are likely to be eaten by a grue.

In reply to Re: 404 page by Dog and Pony
in thread [untitled node, ID 158760] by Samn

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