Presence_penalty and frequency_penalty parameters

The API docs indicate that the range of possible values for presence_penalty and frequency_penalty is from -2.0 to 2.0. Has anybody tried to use negative values for those coefficients?

I’m using GPT-4 for technical translations, so I actually do want repetitions: a certain word might occur multiple times in the source string, and that’s perfectly fine. But whenever I tried going negative with these coefficients, I got garbage results.

Zero should be sufficient for most use cases, unless there are things that have the same name many many times, in which case there is a low probability of that rare item being common in the training dataset.