I was just looking at
http://www.whatwg.org/specs/web-apps/current-work/multipage/browsers.html#the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name
and I noticed that there are some other magical (starting with '_')
browsing context "names" that Gecko, at least supports.
These are "_content" and "_main"; they target the main browser rendering
area. I believe at least _main is supported in IE as well, or was at
some point according to the Gecko code comments (we added _main for IE
compat). These are useful for UAs that allow a non-main rendering area
(e.g. a sidebar) to allow links in it to trigger the main rendering area.
I think it would be good to add one or both of these to the spec.
-Boris
