Multiple fields can be combined to match additional results. Each field, by default, will
      be OR combined with the previous.
    - 
        In the Query Text box, enter:
        
keywords:warship keywords:navy
To return results that only contain both terms, use the AND operator between the terms:
keywords:warship AND keywords:navy
 - In the Results options section, select the check box for Records.
 
The NOT operator and grouping of terms with brackets "(" and ")"
    are supported. For example: 
  (KEYWORDS:warship AND KEYWORDS:navy) AND NOT KEYWORDS:aircraft