The default value for Presence Penalty is 0, which is used when you want to generate text that is coherent with the input prompt, by using words that are present in the input.

On the other hand, if you want the model to generate text that is less restricted by the input, you might want to use a higher Presence Penalty, which will encourage the model to generate novel words that were not present in the input, allowing for a more diverse and creative output.