Besides from the obvious selection-mod-target mod icon, there's also:
target & targetoverlay - just like the hitcircle, target gets tinted by combo color, while overlay isn't
target-pt-1 to target-pt-5 - shards after popping a target
targetoverlay-pt-1 to targetoverlay-pt-5 - same but for the overlay
oh, and the target objects always shatter into 5 pieces