I would like to know how to control the information that is added to a list, not to be duplicated

[ThinhDinh]

How do I create a custom form?

I’m just dropping this here so I have something to refer people to when they ask. This is a simple concept app (copyable), that demonstrates the following techniques: Building custom forms for adding and editing list items (as an alternative to the native forms provided by Glide) Preventing duplicate new entries using User Specific Columns and Relations Enforcing mandatory input items The use of visibility conditions and user specific booleans to control user flow There is nothing particula…

You should be able to achieve that with a custom form. Add a relation from your color entry to the existing list of colors. If the relation is not empty then show the error message and hide the submit button.