[Dev-luatex] "strange" node

Hi, I have this box: \setbox0\vbox{x} when I analyze the nodelist, I find a somewhat strange hlist node: nil : hlist 0> which is referenced from the whatsit (local_par)/prev node pointer. See "n30" in the attached image. Is it safe to ignore this hlist? (is this the parindent box? - answer from the other mail?) Another related question: sometimes I come across "nested_list" and "temp" nodes. Can I ignore these as well? I wonder why two hlists point back to the same nested_list (n155). Patrick (sorry for sending a psd-document in the other mail - graphviz on OS X is really buggy, I exported the graph as a PNG file and it was saved as mybox.png, but in reality it was something else.)