I need help with a Validation rule that basically says if
Account Type = Customer, and you want to set
Account Stage = On going, you have to make sure first that multi picklist field does not contain the value
Do not Know
Is the formula so far, it doesn't work.
ISPICKVAL (Type, "Customer") && ISPICKVAL(Stages__c, "On Going") && NOT(INCLUDES(Multi_picklist, "Do not Know"))