Removable Vertical Board Attachment System

I am building a HO miniature railway on a board 80 cm high.
Below, I put lots of things that my cat loves to explore
I put 10mm boards to make this mess inaccessible to my kitty.
I needed clips to secure the board vertically and be able to remove them easily

I put the middle thing at the bottom between two boards
I put the end thing on the far left and right, bottom
I put the clip thing at the top between 2 boards