After a while working on it, I converted the scratchpad for the routing documentation into a proper patch for Castle's website. Gauthier Segay also contributed some sections, and I hope we can now provide some fixed, formal information on Monorail's current routing system. Thank you to Markus Zywitza for applying the patch.
If you see something that looks incorrect, or something that's missing, then you can help fill in the gaps by patching or just writing it up and someone else will try and create a patch for you.
The next missing docs I plan to address are the fluent registration API for Microkernel, but there are a lot of features I'm not 100% on. Alwin has been doing some great work here so that patch will probably be coming pretty soon. In the meantime, any contributions would be gratefully received!