[NTG-context] symbol parameter of \setuplist

Hello, I fear I cannot figure out what is the meaning of the `symbol' parameter of \setuplist. From all the documentation or mailing list archives, the only use I can find is "symbol=1". Is there a way to use it to draw bullets, say, before each list item, like those in the itemize environment? If not, what would be the best way of achieving this? With \placelist[command=...] maybe? Regards, David