rgsfilter creates the filtered event list as an exact replica of the combined event list, then removes unwanted frames and events, and adds the node-specific exposure maps. As a default option, it also creates the combined exposure map as a separate file. The common practice of including the effective area in the exposure map is rejected because the effective area is handled more correctly by including it in the response matrix. The exposure maps are constructed on the channel space established previously by rgsangles, though each node-specific map is cropped to the exposed area of its particular node. The combined map covers the full channel space, so that channel numbers assigned to the events are coordinates in this map. The combined map is purely an end-product--it is not read by rgsproc or any of its sub-tasks. The filtering options provided by rgsfilter are very limited: events can be filtered on an enumerated subset of the FLAG bits (parameter rejflags), and frames can be filtered by their timestamp (parameter auxgtitables). The filtered event list holds a merged record of all flags and time intervals that have been removed from it.