> you will have to check to see if there already exists a file named navigation.xhtml there, alternatively use ncc.xhtml as filename for the navdoc.

Ah, right there could be a naming conflict. I'm OK with naming the navigation document `ncc.xhtml` (which may be slightly less elegant but is the simplest approach), any objection ?

> Then again, if the NCC is a content document, there will be a ncc.xhtml file there as well.

If the NCC is a content doc there is one singe `ncc.xhtml` file, which serves both as a Nav Doc and a spine item. Any issue there ?