Megacam CCD defects files should be selected according to a keyword present in the image fits header (currently they are selected according to a date).
Independently of the selection mechanism, there are also some questions on the validity of the current defects files. Defects footprints can be generated from the original Elixir defects files.
According to Pierre Astier, for filters i and z, the defects footprints should be enlarged by 1 pixel in the y direction .