This is is Missouri S&T's broken links registry facility.
To handle a broken link, redirect any 404 errors to a URL of the following form:
The broken link administrator app is here.
The broken link report app is here.
There is a sample error document html file in https://brokenlink.mst.edu/sample-errordocument.html, however, you need to download that, and not view it, as your browser will redirect you to the error handling page if you do.