Fan life 팬
Photocard
포토카드 potokadeu
A small card with a photo of a member, in the album.
A photocard is a small collectible card with a photo of one member. Most albums come with one, picked at random.
That is why fans trade them: to get the member they are missing.
Fans shorten it to PC, in Korean 포카.
I got the same photocard three times.