d'accord ... i definitely don't want to argue about a single word, since as a swiss guy, my english doesn't allow for these subtle gradations anyway ;-) i just wanted to give Arnold a few useful answer to his questions. So let's not use "Native" and instead i'd put it that way: At ISO320 the monitor shows just about a pretty true representation of the RAW-Signal and therefore is a pretty good place to be if you need to judge the image you are recording. Whereas at ISO 800 the Monitor "lies" to you because it actually shows a brighter picture than recorded. (Of course this is exactly to make you stop down a little which actually makes you protect the highlights)
It is also worth knowing that the Histogram represents the image with your ISO setting included. But The Goalposts and stoplights don't get affected by the ISO-Setting. So if you want to "Expose to the right" i think its best to judge the histogram that represents the RAW-Image as closely as possible i.e. @ISO320.