Quoting Peter Gerdes, from the post of Mon, 16 Aug:
Anyway, I'm trying to create a wiki which needs two pages associated with every article. For each article I want both a discussion page and an explanation page. While I could just require everyone creating a page X to also create exp_X this isn't particularly an elegant
a very uneducated guess, but I imagine it should be easy to clone the discussion namespace and add another tab in the skin...