... badpix collects together pixels identified as containing no useful data, and uses this information to produce a badpix extension table to either the input raw events file or a copy thereof. ... A very important point regarding the bad pixels is that there are essentially three separate (though not exclusive) sets of bad pixels that must be dealt with. ... In the case of MOS, the task accesses the uplinked (set 1) bad pixels from the actual ODF data files of the observation in question. ...