Fence filters are used in conjunction with the Generate Report Table tool and also to generate reports in the form of plotted designs. A fence filter specifies non-graphical criteria used to select elements for fence operations. Report tables generated using fence filters contain only rows for elements contained in the fence that meet the specified criteria.
This has the added advantage of allowing you to graphically work with the selected elements.
The fencefilter row in MSCATALOG contains fence filter specifications. Each table listed in MSCATALOG can have a unique fence filter.