I have a multiselect picklist with ten values. One of these values cannot be chosen more than once on a record..
multi_sel_picklist__c = "Aa" can only occur once on a record, with no duplicates of this value.
I tried this but it doesn't work:
(INCLUDES(multi_sel_picklist__c)"Aa", 0,1) > 1
Is it possible to validate that a selection is chosen only once? If so, how?
multi_sel_picklist__c is a on a custom object (Custom_Obj__C) and is linked to Account. You cannot have multi_sel_picklist = 'Aa' on the same account.