Transfer function in shopping list - what does it do?

[bfg100k]

Hi all,

I'm a new user and just discovering the shopping list feature. I have 2 questions -

1. Is it possible to move items from one list to another? If so, how?
2. There is a "transfer" option when I click on the "dots" button to the right of an item. I tried clicking it and nothing seems to happen. What exactly does it do?