Transmission reverse proxy

All right, I have to write this down before I forget. I spent the better part of the day figuring this out, so here it is in case I ever need this again.

I wanted to set up a short URL for transmission-daemon on my NAS so that instead of awkward http://nas:9091/ I could type something more finger-friendly (most notably, without the colon for port number), ideally http://nas/t/. Here is the final config that resulted after several hours of research and apache2ctl restarts:

<VirtualHost *:80>
        ServerName nas
        RewriteEngine on
        RewriteRule /t[/]?$ /transmission/web/ [R=permanent]
        ProxyPass /transmission http://127.0.0.1:9091/transmission
        ProxyPassReverse /transmission http://127.0.0.1:9091/transmission
</VirtualHost>

Thanks to everyone on forums and StackOverflow for numerous solutions that allowed me to piece this all together.