How does 'Sort items by Manual and ...' work?

I am trying to figure out the function of the ‘By Manual and …’ sort options for items (the bottom two options in the picture below). I cannot find any documentation about this. I am looking for a way to determine the sorting sequence myself and I was testing these options in v7.1 for that purpose. However, I cannot notice any difference between ‘By Name’ or ‘By Manual and Name’.

What is the purpose of these options?

2021-01-13 16_09_18 digiKam

With “By Manual and Name or” By Manual and Date "you select the presorting for images that have not yet been manually sorted. If your images are fresh out of the camera, there will be no difference between name and date. Now you can drag&drop images over another image (position). A popup appears and you choose “Insert Here”.

Thank you, that was exactly what I was looking for.