Filtering is performed by invoking the Filter..." button in the main toolbar, and specifying the filter specification in the filter dialog. The filter dialog is used to specify the characteristics of individual result items which are used to determine which items are active in the displays. Filters can be saved and reloaded at a letr time using the "Load" and "Save" buttons in the lower left hand corner of the dialog.

Individual characteristics of result items are specified by selecting an attribute, an operator, and one or more values which are to be tested using the selected operator. Multiple values specified for an individual text characteristic are tested serially, and all result items which match based on the attribute, operator, and any individual value are considered to match the specified characteristic. Numeric characteristics are specified as a range defined by two input values. Specifying both values will include all items inclusive in the range. Specifying only the lower limit or the upper limit will include all items above or below the limit inclusive, respectively.

Multiple characteristics can be specified (using the [+] button) and are considered in parallel to determine the subset of result items that match all specified characteristics.

Multiple groupings of characteristics can be specified by invoking the [||] button in the leftmost column header to create additional groupings. Each grouping of characteristics is considered serially, and all result items matching the characteristics of any group are made active. Groupings are portrayed using alternating background color.

Any individual characteristic can be removed by invoking the [X] button at the rightmost position of each line.

The filtering mechanism provides enumerations for some attributes. If an attribute is enumerated, then the query panel will display the […] button to the right of the value(s) editor. Invoking the […] button will cause the value selector form to be displayed.

The value selector form is used to select one or more values to be included for the individual characteristic. Available values are shown in the listing on the left. Included values are shown in the listing on the right. Both listing support the selection of multiple items using the <ctrl> and <shift> keys. With items selected in the available values listing, the [>] button will cause those values to be represented in the included values listing. With items selected in the included values listing, the [<] button will cause them to be excluded from the included values listing. The [>>] button will cause all values from the available values listing to be included in the included values listing. The [<<] button will cause all values to be excluded from the included values listing.

The filter field is used to refine the list of available values based on one or more keywords or phrases. When keywords are present, separated by white space, the available values list is restricted to only values that contain all of the keywords in the filter field. Keywords containing white space may be entered by surrounding the keyword with the quotation character.