Should it be possible to nest nevow:data declarations in a template? E.g. <html nevow:data="order" nevow:render="order"> <head><title>Order <nevow:slot name="order_number"/></title></head> <body> <h1>Order <nevow:slot name="order_number"/></h1> <ul nevow:data="order_items" nevow:render="sequence"> <li nevow:pattern="item" nevow:render="mapping"> ... slots and stuff </li> </ul> </body> When I do this I get a big long stack trace rooted in nevow/accessors.py. It works fine if I remove the outer nevow:data="order" (and dummy up a static fillSlots call for "order_number" in render_order). It also works if I remove the inner section. I can work around the problem by putting the nevow:data="order" declaration in multiple places but it would be handy if I didn't have to. Is this a bug or is it by design?