Sets or returns the category of the spreadsheet. Windows can search for an Excel file using the category property. 

 public System.String Category{ get; set; }

Public Property Category() As String


          //--- Get Category
          string category = docProps.Category;

          //--- Set Category
          docProps.Category = "Sales Reports";
        

          '--- Get Category
          Dim category As String = docProps.Category

          '--- Set Category
          docProps.Category = "Sales Reports"