Question about eponymous template trick

[Uranuz via Digitalmars-d-learn]

> Looks like compiler looks for Node, Name and Attr in Node 
> struct, because of eponymous thing.

I understand it but I want to know if it is documented behaviour 
or not. Could anybody clear what happens with eponymous stuff and 
why I can't get acces to *other* declarations inside eponymous 
template? I guess that it is not intended behaviour.