FogBugz has two fields, Version and Computer, used to keep track of the version of your software where a particular bug was found, and the computer or computer configuration on which it was found. These fields will not necessarily make sense for every development team, so the fields can be turned off to reduce clutter, or re-named as something else if there is something else which you need to track. You can then include these fields (whatever name you give them) in your filters.
