Apologies Luceos - it looks like my reply needs approval, probably because I included a link to a picture on Onedrive..
What I was thinking of is an easy way for people to look at a conversation and to be able to follow just one branch, or at least to clearly see which post the reply is to.
The forum will be about philosophy. I hate threaded email views, but for in depth discussions you often end up with completely different subjects being discussed under an original post. If they are all mixed in together then it's very difficult for people to follow. Whereas if you click into one of the posts with many replies on the example forum I shared above, you can easily see and follow the different branches of the discussion.