Hello Davidfor, Thanks !!! now it's clear and working in this direction !!!
I tried to follow your first post to copy collection from my device to Calibre and it's not working... : in fact I do like this :
I created one new collection into my device (the second one),
I put one book in this collection into my device,
I started Calibre,
I connect my device,
I used the function "Get Shelves from Device" of Kobo utilities => I select "#tags" => OK
The result was :
- no creation of my second collection into calibre
- no change on my first collection on my device & calibre ( yes

)
- removal on the only one book into my new collection into me device
- My new collection (the second one) is still alive into my device !!!
Thanks again for your help for this step !!!
Jean Marc