When declustering a catalog of earthquakes, the goal is to identify and remove aftershocks or other events that are temporally and spatially related to a larger, main event. The treatment of repeated events with the same location, date, time, and magnitude can vary depending on the declustering method used and the specific criteria applied.

In most declustering algorithms, repeated events with identical attributes are typically considered as part of the same seismic sequence and are not counted as separate main events. Instead, they are treated as aftershocks or duplicates of the main event. These repeated events are typically identified based on their temporal proximity and spatial proximity to the main event.

When declustering, the main objective is to identify and isolate the largest, most significant event in a sequence, such as the mainshock. The subsequent events that occur within a certain time and spatial window after the mainshock are typically considered aftershocks and are removed from the catalog or assigned lower weights in subsequent analyses.

It's important to note that different declustering methods and algorithms may have slightly different criteria and rules for identifying aftershocks and determining their relationship to the main event. It's recommended to consult established declustering algorithms or seek expert advice in the field of seismic analysis to ensure proper handling of repeated events in your specific analysis.