Board rules tell the Kanban participants what is required to for a card to move to the next column of the board. If each column could have the ability to open like cards do, column information could be stored there. The only alternative to add this information would be with a comment.
This is one of my team’s blockers from using the Kanban framework board on Miro. Having board rules that can be toggled would help us be able to see the progression of cards without so much clutter.