It's a lot of work because I need to customize URI structure in blog systems and put complex rewrite rules.
To ensure the setup is more or less correct, I have a bash script that tests the redirects via curl. https://bitbucket.org/yoursunny/yoursunny-website/src/912f25...
The original site ran on IIS and was old enough that MS software at the time still used three letter extensions for backwards compatibility, around 1997-1998 IIRC.
Kudos for maintaining that compatibility, but it seems that this kind of thing is addressed in the linked document:
> File name extension. This is a very common one. "cgi", even ".html" is something which will change. You may not be using HTML for that page in 20 years time, but you might want today's links to it to still be valid. The canonical way of making links to the W3C site doesn't use the extension.