You can define a set of exact conditions for a case type. By identifying which attributes of a case are required, you can improve the performance of your duplicate-search logic because exact conditions limit the number of cases to evaluate as potential duplicates.
    
    - 
        In the  Explorer  panel, click  Case
            types, and then click the case type that you want to open.
      
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         On the Settings tab, click Track
            duplicates. 
      
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        Ensure that a threshold and at least one weighted condition are defined.
        
      
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         Select the Configure must match conditions check box. 
      
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         Click + Add condition. 
      
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         In the Label field, enter a short, unique string that
          identifies this exact condition. 
        
          
            Tip:  You can keep the default labels that automatically increment each time
              that you add a new condition. For example, A and B are assigned to your first and
              second conditions respectively. These labels are easier to reference in the
                Filter logic field.  
 
 
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         In the Potential duplicates field, press the Down Arrow key and
          select a property name. 
      
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         Select a function from the Operation list. 
        
          For example, you can verify that a property does not start with the string
            "Customer". 
 
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         In the Filter Value field, press the Down Arrow key and select
          a property name. 
        
          The function that you provide in the Operation list compares the
            value in this field with the value in the Potential duplicates
            field.  
 
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         In the Filter logic field, enter Boolean logic that considers
          each condition. 
        
          
            Tip:  You can use traditional Boolean operators or the keywords
                AND,OR, andNOTin your logic.
              Use parentheses to control the order of operations. For example, you can enter (A AND
              B) OR (NOT C).
 
 
 
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         Click OK. 
      
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         Click Save. 
      
Exact conditions and your filter logic are evaluated first to narrow the list of potential
        duplicates. The results of your filter string must return a true value before weighted
        conditions are considered.