Select an item and not show it again.

[phornsophon]

Hello, Community
            I have something to help, When we select an item in the list I don't want to show again ,What are the steps or methods?

[Marc_Dillon]

https://help.appsheet.com/en/articles/961544-dropdown-from-valid_if

https://help.appsheet.com/en/articles/4575802-list-subtraction