difference between nudism, naturism and FKK

The official wording of the federations is: there is no difference. We have to accept that all and everybody is equal. I agree with that and I understand the intention. But I would like to differentiate. (what we do anyway whispering) I would like to differentiate with keeping in mind that in the end all movements and all participants are equal and we are open and respectful. To understand the difference you have to understand the history. I think we all are students here. Nudism has its origins in the USA, naturism in France and FKK (free body culture) in Germany. These countries have different cultures and different history by itself. So they influenced the movements. I was positively surprised by this text about the history of nudism on the AANR website: https://www.aanr.com/aanr_articles/the-history-of-nudism/