I have custom list in SharePoint 2013. That custom list made in element.xml and schema.xml. I am trying to put validation on list field using below method. For ex : https://docs.microsoft.com/en-us/sharepoint/dev/schema/validation-element-list But it doesn't reflect anything on SharePoint side.
Is anyone done this before? If yes then can you please suggest me the best way? And I am even not sure how to put that script in validation element.xml