I Googled, and I think they mean photo "splits". Found these on Amazon with some comments about them:
https://www.amazon.com/Scotch-Photo-...dp/B00NHVDIC6/
I don't think they're like the old photo corners because the splits don't show on the front.
Edit: These repositionable ones might be better, as they are removeable. One review says they have the type of sticky that post-it notes have. You just have to be sure you get the right kind.
https://www.amazon.com/Scotch-Reposi...dp/B00MWTKMIM/