127.can't be a normal domain
your local address is it's only name
the subdomains contain nothing at all
but point instead behind your firewall
---
everything.127.ca (that is *.127.ca) is mapped to 127.0.0.1 (your localhost)
I use this for running virtual domains on my own systems - no local dns required
you can use it for whenever you need one or more domains to point to 127.0.0.1
---
127.ca is part of the ravis dot org network