[NTG-context] How to add a new unit for \unit{} command?

Hi all, I want to add new units to the \unit{} command but I can't find how to do it. I found that one can changes existing units with the following luacode: languages.data.labels.units.whatever = {Meter = "retem"} but I found nothing to add new ones. I would like to have, for exemple: \unit{50 milli volt per division} to give: 50 mV/div. Thanks in advance. -- Romain Diss