Warning
As I have discovered to my cost when using the format function from the memory options , it does exactly that, it completely erases the card and if you have made a mistake you cannot recover
images with a recovery program; the sony A7RII does a full format.
Well what did you expect I hear you saying, i expected to be able to reverse that's what, if I format a card with my Olympus body or any of my Pentax bodies I can still recover images and I was used to that fail safe if I messed up.
Don't fall into the same trap, if your Sony say format then it b****y well means it!!