[whismerhill]

Thanks for the answer,
but unless I misunderstood (I'm french) that's not what I'm looking for.

What I want is basically a list that takes a snapshot of what's in my device at a certain point in time of my choosing.
For now I manage to make it by changing the type of list it is when I want to sync it

example usage : I take a snapshot of what's in my wife's ereader before I delete & add books to her device, that way if I made a mistake I can easily check out the snapshot list I took before to revert changes.

so in this case after the sync is done, I change the type of list it is to manually updated so that's it's not synced again on next ereader connection. (which would defeat the purpose of that list, which acts like a sort of "history")

My only gripe with my method is that I HAVE TO not forget to set back the list to manually after a manual sync otherwise it might just overwrite it on next ereader connection. Hence why I was looking for another way to do the same.


EDIT: basically if you could uncheck the "sync to this device as soon as it is connected"
when using an autopopulated list. It would be perfect. but maybe there's another way ?
because I learned that in calibre there's often more than 1 way to do things. And sometimes some things which are not possible at first become possible with some work around. (example yes/no read status columns can't go in the tag browser, but use a custom column that extracts the yes/no value as a tag & there you have it in the tag browser)